This is a broad topic, so I'm going to try to narrow it down as much as I can. I've talked about why I spec the way I do in a more general sense, so I'll not do that again here. I've also dedicated two posts already to the tactics that I use with this spec, so I'll not waste my reader's valuable time with recitations of that either. What I am going to do is list every single talent in the affliction tree, and why I did or why I did not put points into it. I'll also briefly mention at the end of this post why I decided to put my extra points into destruction rather than demonology, and why I decided to place them in the places that I put them. Hopefully by the end, I'll have a comprehensive guide for locks looking to spec affliction for the first time--even if they don't make the same choices I made.
I'll warn you right now that this post is going to be rather long, though I'll do my best to keep it from becoming dry. So, without further arbitrary addition to the already sizable length of this post, here's my spec:
Improved Curse of Agony (0/2): Right off the bat is perhaps my most controversial decision. Almost all affliction warlocks these days--and even many demonology and destruction warlocks as well--put two points in here for the improved damage. I, too, would join them, save for the unfortunate fact that I don't have any boomkin or deathknights to run with reliably. This means I'm still casting Curse of Elements frequently enough that it doesn't seem worth it to spend two points on something I would only get to use very occasionally.
Suppression(3/3): Three points here makes getting myself up to the all-important hit cap much easier. However, if I ever reach the point where my gear easily gets me all the way up to the spell hit cap of 446 (which it almost has by now) then these three points will very likely start going elsewhere, since the mana-cost reduction to my affliction spells is insignificant. Two of them will probably go into Imp'd CoA, if I haven't already moved points into there by then.
Improved Corruption(5/5): This is an absolute, and obvious, must for all affliction warlocks. Corruption one of the most important spells to any affliction rotation--and in fact as of late I've noticed that it has become my single highest damaging spell, beating out shadow bolt by 1% of my damage dealing pie. As such, improving it whenever possible is crucial. Any affliction lock who doesn't r lyke ttly skrub. Also ghey, lawl.
Frailty(0/2): Despite being improved since Burning Crusade, this talent is still absolutely terrible, and should never be taken. Evers. Double ever.
Improved Drain Soul(0/2): This talent is something of a tossup. It's a soloing/PVP talent, so in a raid or instancing environment it helps only a very little bit. However, the rather lackluster talents of tier 2 make this an acceptable choice, if only to give you enough total points in the tree to make your way to the next tier. It's certainly a fine alternative to putting any points in Frailty.
Improved Life Tap(2/2): Life tap is fundamental to a warlock's ability to do damage. Our spells are mana inefficient, we can't regen mana the way priests or magi do, and the only way we're going to be able to keep casting is if we're able to life tap or dark pact to keep our mana up. I would go so far as to say that this is a must-have talent (though more due to the poor choices on this tier than to how awesome an extra 20% mana is I think.)
Soul Siphon(2/2): Much to my embarrassment, I only recently noticed that this talent was changed in the Echoes of Doom patch. You can tell I'm smart because it only takes me three months to notice a fundamental change in a talent that I've put points into after several respecs. Having now noticed it, I am tempted to move these points either to Improved Curse of Agony, or to Improved Drain Soul. However, Drain Life is very helpful when soloing Onyxia--which is fun even though they recently halved the gold you get from doing it. So I may keep it here. Regardless, I don't view it as important enough an error to deal with immediately. After all, it's not like I put the points in frailty. (Which you should never do. Ever.)
Improved Fear (0/2): I imagine that this is a kickass PVP talent. It's probably also sexcellent for soloing. However, I do not PVP, nor do I use fear much when I'm soloing things. I'm weird that way. As such, I've never put points here, and doubt I ever will. Cool talent though.
Fel Concentration (3/3): Another great soloing talent that ends up being completely useless in a raiding or instancing scenario; provided the healer is doing his or her job. However, since there really isn't much else to put points into at this tier, I think it's a good choice, since without this talent, drain-tanking is effectively impossible.
Amplify Curse (0/1): I'm bouncing back and forth on this talent. It was initially very appealing to me, so I took it to try it out. After leveling up with it, and using it in my first raid or so, I concluded that it was a bad talent for me. My conclusion was based on the fact that I always used Curse of Elements, and my typical tactic for using that spell was to cast it while the tank was gaining aggro. As such, a faster cooldown didn't mean I got to start DPSing faster, because I was waiting for the tank to build aggro anyway. I even went so far as to sugguest on the warlock forums that this talent be changed so that it reduced the global cooldown of lifetap and dark pact--spells that often need to be cast in the heat of casting rotations, which has a tendency to throw off a person's sense of timing. However, due to how much easier threat generation has become, and due to the increased use of Curse of Agony in modern raids, I am beginning to reconsider whether or not this talent would be useful. My personal jury is still out on this decision.
Grim Reach (0/2): The equation with this talent seems very simple in my mind. Any affliction casting rotation I've ever seen contains shadow bolt. Most good ones also contain Immolate. Immolate and Shadow Bolt are destruction spells, and will not get the increased range from this talent. So, unless you're willing--and able--to put points into the destruction talent which also increases range, Grim Reach is silly, because you'll still have to stand just as close as you would have without it in order to cast your destro spells. Furthermore, I've noticed a distinct lack of fights in Wrath of the Lich King which really require you to stay as far away from the boss as you can. In fact, there are a surprising number of fights where you actually have to stand on top of the boss in order to be successful. Perhaps things will change in Ulduar. If so, I shall reconsider.
Nightfall (2/2): I'm a bit dubious about the amount that this talent actually helps, but again, poor alternatives leave me with only a few equally dubious alternatives. I've heard that the benefits of this talent are much better now than they were in BC, which is good, because I have points here. It should be noted that Glyph of Corruption DOES stack with this talent, so it's probably a decently good idea to get both--given the lackluster quality of warlock glyphs. (A subject I should probably write on sometime soon as well.)
Empowered Corruption (3/3): Woot, another chance to improve my corruption. If I didn't take this, I'd be a moron!
Shadow Embrace (5/5): This talent is an absolute requirement for any affliction spec. In general, things that make ALL your dots do extra damage are a very, very good thing. This is also the reason why, in my boss rotation, I open up with a shadow bolt before I cast haunt, followed by all my dots. That way, this effect is stacked to the maximum of height of two before my first dot ticks.
Siphon Life (1/1): Siphon Life, even after being Glyphed, will probably end up being your lowest damage-dealing DoT. However, without it your overall damage would still be significantly lower. What's more, the healing effect (combined with your Fel Armor's heal, combined with the healing effect of Haunt, combined with a Death Coil now and again) help you keep yourself healed through all that life-tapping you'll be doing during boss fights. The healing effects mentioned are enough, in fact, that it allows affliction warlocks to solo some rather tough elites with ease. Not only is this talent useful enough that you should get it for instances and raids, but it's also an utterly fantastic talent for both soloing and PVP.
Curse of Exhaustion (0/1): A dubiously useful talent, that requires you to take another dubiously useful talent. Curse of Exhaustion is great for PVP, and a very useful tool when soloing, but for a spec geared toward group-content, you really can't allow yourself to waste the point most of the time. (Not to self: find a thesaurus that has terms such as 'PVP' and 'soloing.')
Improved Fel Hunter (0/2): This is a decision I may have to seriously reconsider. The primary benefit of this talent is that it allows your fel hunter's main attack to return mana to it--which in turn allows you to dark-pact mana from your pet more frequently. (it also improves the Fel Intellect buff, but I did the math on it once, the improvement is utterly negligible. Not even worth considering the the decision making process.) Now previously, I rejected this talent because on 98% of bosses in the game, if I sent my fel hunter in to attack them they would one-shot him with some kind of AoE or whatever. However, due to the recent change (which raised my fel hunter's health from 7k to something like 17k unbuffed) the fel hunter may be significantly more capable of surviving, making this talent much more viable. I will do testing on this over the next few weeks--though my initial concern is that the fel hunter will only last slightly longer than he did before with this new HP buff, since I refuse to waste valuable casting time using a channeled heal on my pet. We will see, however.
Shadow Mastery (5/5): RAWR, Shadow Damage! Even if Siphon Life were the most useless spell in the game, it would be worth getting it just to get your hands on this talent. The only spell in my rotation that this talent doesn't improve by 15% is Immolate.
Eradication (1/3): Eradication is an interesting little talent. I, like many other affliction warlocks, once had it topped out at 3/3, until I saw the math. See, the way the internal cooldown for this proc works (it's unusually long) means that if you increase the probability of it happening, as you would by putting two or three talents into it instead of just one, all you really do is cause the ability to proc during the cooldown--meaning essentially that one point in here has almost exactly the same benefit as having three! Do yourself a favor and put those two points somewhere more useful. (I put them in Cataclysm, which made me hit-capped.)
Contagion (5/5): 5% isn't all that impressive for a 5-point talent, and the dispelling effect is really just for PVP, so it's not really a viable reason for taking this talent in a PVE spec. However, a buff to corruption is a buff to corruption. I've never seen a good affliction warlock without this talent, and I doubt I ever will.
Dark Pact (1/1): Dark Pact has gotten a lot of heat lately. Many warlocks feel that it scales poorly compared to lifetap, and has been rendered useless. Now, one or two people complaining about that and I would disregard it as poppycock spouted by morons who can't play their class. However, it is a complaint that is gaining a great deal of purchase in the warlock community, so I decided to do some tests myself. I won't bore you with all my numbers, but what it comes down to is that Life Tap returns roughly 2800 mana, and Dark Pact returns about 2800 mana. There are variances as my stats change, but all in all they usually return within 200 mana of one another. Pet mana and personal health regen are such that I'll likely only be able to get 2 Dark Pacts off before the pet is empty, but if I'm wise enough to dark pact early on in my rotation, rather than when I'm out of mana, I should be able to get away with going 50/50 between life tap and dark pact, which will be a great help to the healers. Now, it should be noted that these numbers may be vastly different for different people, because Dark Pact scales depending on a warlock's spell power, and Life Tap scales--as of 3.0--depending on how much spirit a warlock has. However, I don't see any reason why my spirit / spellpower ratio wouldn't be at least roughly representative of most level 80 warlocks. Perhaps I am wrong in thinking this, I don't know. That said, pets COULD use a larger mana pool. This is something I'd really like to see from blizz in the near future. (They do seem to be reconsidering the dark pact mechanics, given the various PTR changelogs I've seen over the last 6 months.)
Improved Howl of Terror (0/2): I wish this talent was viable for PvE ;_; It's just so bloody awesome. An instant cast fear? Holy crap is that cool! Unfortunately, a warlock should only rarely use fear in an instance, and this deep into the tree you have to start being very frugal with your points, because almost everything is necessary to take.
Malediction (3/3): While the 3% bonus to spell damage that they added makes these three points worth it all by itself; I largely took this talent for the improvement to Curse of Elements. By this point in reading this post / my blog you should be more than familiar with why.
Death's Embrace (3/3): While the bonus to draining is a boon for soloing and PVP, the improved crit chance is really what makes this talent worth taking. Warlocks have a notable lack of 'cooldowns' to 'bust out' when the raid leader starts shouting "ALRIGHT, SHE ENRAGED, BUST ALL YOUR COOLDOWNS!" So this talent is really very helpful in giving affliction damage a little extra 'umf' in the home stretch. (I actually covered exactly what that umf amounts to very recently.)
Unstable Affliction (1/1): Must have. Period. Second best warlock DoT there is.
Pandemic (3/3): This is an astoundingly interesting and innovative mechanic, and it's one of the biggest reasons that affliction is able to remain competitive in Wrath of the Lich King. See, in Burning Crusade, warlock raiding went like this: first, you spec affliction. You get to about SSC / TK level, you get the magical stats (202 hit, 20% crit, 1200 spell damage if I recall correctly) and then you respec 0/21/40. Why? Because affliction didn't get much of a benefit from all that crit, and since your gear ended up having crit rating on it anyway, destruction was indisputably more powerful than affliction at this level of gear, by several orders of magnitude. The size of a destruction warlock's crits in BT gear are seriously something I didn't start to see on Sentai until he was Naxx-geared at level 80. So anyway, in response to this, blizz created Pandemic, which (essentially) allows dots to crit, allowing affliction to scale with gear in a way that it was unable to do previously. It's really quite ingenious. That said, I'd like to see the effect altered somewhat to include all periodic effects, rather than just corruption and unstable affliction, because based on what I've seen on my damage meter's pie charts, pandemic isn't doing quite enough damage to really keep affliction competitive with destruction in T9. However, we will see as time goes on! (I should also note that blizz recently said that they had managed to re-code the way dots work in such a way that they could--if they wanted to--allow dots to crit on their own. They also said that they have no plans to do that at this time; but it could be an interesting mechanic in the future.)
Everlasting Affliction (5/5): As if the additional spell damage wasn't enough to make this talent worth taking, the fact that it allows Haunt to re-apply corruption is a beautiful thing. You see, with Haunt re-applying corruption, a whole spell--and its 1.5 second global cooldown--are removed from the extremely complicated affliction rotation. As much as I love the depth of affliction DPSing, I welcome this bit of simplification with open arms. I would like to see the talent modified in the future, however, so that Drain Life does NOT renew corruption. Drain life has a rather short duration--particularly if the warlock is getting hit. And most of the time when you're casting Drain Life, you're casting it over and over again--meaning that your corruption spell often doesn't even last long enough to get a single tick off before drain life re-applies it. [EDIT: I stand corrected on this! Apparently the re-application of corruption caused by this talent does not break the flow of damage ticks. My bad!]
Haunt (1/1): Haunt is living proof that blizz is full of smart people. This is exactly the kind of innovative mechanic that I love to see. All at once, it both plays to the already established strengths of this spec, while also bringing something completely new and unfamiliar to the table. Bravo, warlock dev team. Bravo.
With 54 points spent in affliction, that leaves me with 17 points. There are a multitude of interesting things that could be done with those points. For example, 13 points in the demonology tree to grab Demonic Aegis would not only increase the amount of healing Fel Armor does by 30%, as well as turning the 180 base spell power from that spell into 234, but it would also convert 40% of my spirit into spell power, instead of the default 30%! However, as you can see I haven't done that in this spec, as tempting as it is. Instead I've put those 17 points into the destruction tree, due to the fact that the low-tier talents in that tree are more useful for straight DPS than the low tier talents in demonology. At least, that is, on average. As stated above, I'll only go over the talents I actually took in the destruction tree, for brevity's sake.
Improved Shadow Bolt (5/5) This is an astoundingly good talent, particularly for affliction warlocks, and particularly since the recent change made to it in 3.0. With five points here, every single time your shadow bolt crits against a target ALL OF YOUR DOTS (except immolate) do 15% more damage for the next 12 seconds. And let me tell you, even as an affliction warlock, I crit quite frequently. What's more, as of 3.0 the effect is now a buff for the warlock, rather than a debuff for the target--meaning the bonus damage will hurt all of your targets, rather than just the one which you crit against. I can't imagine going without this talent.
Bane (5/5) Back in Burning Crusade, when I was hanging out on the warlock forums trying to figure out what the hell I was supposed to be doing, I heard a warlock say 'there's no such thing as a raiding spec without bane.' And as far as I can determine, this has only become more true for affliction warlocks since Immolate is part of our rotation now.
Cataclysm (2/3) This is a recent addition to the Mach 3 version of my affliction spec, and wasn't here in Mach 2. Much like suppression, I have this talent to shore-up my hit rating numbers. With the combination of those 5 talent points spread throughout the 2 trees, I am far above the hit cap for all my offensive spells. When my gear eventually reaches the point where I'm easily maintaining the 446 hit, I may decide to move these talents into something more useful, since the mana-cost reduction is (as mentioned) negligible.
Ruin (5/5) Sexy, sexy ruin. There isn't a warlock in the world who doesn't want to have the five talent points to spare so they can put them here, thanks to the way Blizzard rearranged the destruction tree in 3.0, I now do. This makes my shadow bolt crits very big. They're like..."BOOM!" and seeing numbers like "9538" on my screen causes some of the bloodflow in my body to be diverted elsewhere, if you know what I mean. *wink wink*
So there you have it, the grand spec post. Kind of daunting, now that I look back on it. I hope I didn't get anything massively wrong, since this post is likely to be one that a lot of people find my blog from. But hey, couldn't put it off forever right?
Anyway, despite the fact that I can't quite think of a way to end this post, anybody who read this far is doubtless hoping that this post is going to end soon, so I'll grant their wish without any further delay.