The thing about balance
Out of all the changes in 4.2, there weren't actually all that many for warlocks. In fact, there was only one -- a nerf to the Glyph of Soul Swap. To me, this was actually a very good sign. While no spec is perfect and there are certainly things about warlocks that I would like to see changed, it shows that overall the three specs are all doing rather well. The best part: It's even true!
In terms of damage, all three specs can do respectably well. I personally wouldn't feel as though I were a liability to my raid no matter which spec it was that I choose to play. That's a wonderfully great thing. Sadly, however, damage balance is not the perfect equalizer. Once damage is balanced, perspective shifts to other factors such as utility.
In the previous raiding tier, we had close to the same damage balance that we have now, yet certain fights simply favored the utility offered by certain specs so much that not playing in those specs seemed detrimental. Not being demonology for Maloriak was viewed as a mistake a majority of the time. Cho'gall could go 50/50, at least. The high AOE requirements of the encounter favored demonology more so than any of the other specs, yet Worship favored destruction heavily due to Shadowfury.
When damage doesn't matter, utility or the strength of the spec begins to count for more. Not all utility is created equally, and certain encounter mechanics will always end up favoring the advantages of one spec over that of others. That isn't an issue, provided that you have a variety of encounters that favor a variety of specs. That way no one spec vastly outshines the others.
Even though the prior tier had many encounters that heavily favored one spec or another, that they all favored different specs was a great bonus. You could be a destruction warlock primarily but keep a demonology spec for AOE encounters. Or you could pull off being demonology with a side spec of affliction for extra self-healing and cleave damage.
When utility takes a hit
It's a major deal when the utility of a spec is reduced in any way. Despite the lack of changes this cycle, the one that we did see was rather significant. Affliction is currently our highest DPS tree by a small margin, yet it still holds that small edge in dual-target damage. That's been reduce; the question is by how much.
Destruction is perhaps second when it comes to dual-target damage with Bane of Havoc. The matter, however, is one of scaling. Affliction's dual-target damage did (and still rather does) scale slightly better in dual-target situations than destruction does, not in terms of how much damage it gains but how much that damage gap will continue to grow.
By increasing the cooldown on Soul Swap when the glyph is used, this significantly hurt the viability of using said glyph for PVE. More than that, it hurt the dual-target damage nature of affliction.
Although I don't really support that a form of damage should be the "utility" of a spec, it happens from time to time. Also, not every encounter requires dealing with two high-health targets at the same time, so having that being the strong point of a spec isn't going to entirely break anything within the game.
By reducing that for affliction, the identification of that spec is rather diluted. It may just be me, but I like the differing damage styles of each spec, and I feel that Blizzard should focus on those strengths more. Having affliction perform best in two targets and demonology bring the highest AOE while destruction provides the highest burst potential would be a fantastic balancing point.
Different encounters require different things, so it would be nice to have those options. This offers the customization that players want while not actually creating any imbalances. Trying to shove all of these things into every spec is how we end up with every spec being so boiled down. We need to understand the difference between having a strength in one area and a spec being passable in that area.
About encounter design
In Firelands, the encounters that we face are all rather unique. Nothing favors the requirements that we saw in the previous tiers. Beth'tilac, for example, requires strong AOE and control abilities, but it also requires high single-target damage from a variety of sources. A demonology warlock might be better off handing the smaller adds that need to taken down, but you could still work in an affliction or destruction warlock taking down Beth'tilac or the drones.
This is why it is so important for each of our specs to have its own little niche that it can fulfill. Even though each encounter requires something different, not every encounter is only going to require a single form of damage; even AOE-heavy encounters still need high single-target DPS players, too, in a variety of situations. Problems occur with entire classes feeling "useless" when they cannot, under any circumstances, perform the requirements of an encounter.
Without the high AOE of demonology, warlocks wouldn't feel nearly as useful on Halfus or Maloriak as they did. Although neither affliction nor destruction are terrible at AOE, they clearly don't have the same strength of it as other classes/specs do. That, I feel, should be the "advantage" of playing a pure DPS class.
A hybrid spec may have a strength in one area, yet a pure class should have the ability to change to suit the encounter design.
While warlocks themselves are one of the best when it comes to this level of balancing, even our class still has quite a long way to go. The burst abilities of destruction need to be increased, and the dual-target damage of affliction needs to be brought back to the level it was at before.
In terms of raw, single-target damage, we are perfect, flawless. We have fantastic balance between all three specs to enough of a degree that we can choose whichever we want to play. As much as spec choice should be about fun, it should also be about encounter flexibility. It is nice that Blizzard caters, so to speak, to more casual players, yet I don't feel that this has to be at the expense of the more hardcore players.
Blood Pact is a weekly column detailing DoTs, demons and all the dastardly deeds done by warlocks. We'll coach you in the fine art of staying alive, help pick the best target for Dark Intent, and steer you through encounters such as Blackwing Descent and The Bastion of Twilight.