I noticed this as well. I also noticed how little it was commented on by this site and others when the AOE buffs to all classes were released.

They did and they have, it's just they went a little TOO far with it, Blizzard, for example, is getting a 70% buff, because its mana cost was prohibitively high, and its damage was relatively low.

Yes indeed, I think that this is a shift back towards some use of AoE on fights, but I think only on boss fights. Encounters like Magmaw are such that a fairly junior raiding guild will have a hell of a time with his maggots. I know for a fact that without at least 60% of our DPS being ranged on that fight, we can't beat it, though we are only JUST getting into raiding. It is my belief that some of these AoE buffs will be scaled back if people are finding ZA and ZG too easy, and if tanks are finding the quickest way to down a pull is to just grab everything and depend on AoE's as was the Wrath style.

Honestly, AoE should only be for grouped-up adds like Magmaw's larva, and trash pulls with more than five targets. Any other situation should be single-target DpS, with CC's on each pull. Personally, I kinda hope Blizzard buffs up the current heroics, if in numbers if nothing else, to match the standards of newer heroics. Though, seeing as people would bitch about harder dungeons and blizzard has already divided heroics into teirs, that's not likely to happen.

They said they wanted to shift focus away from AoE. They did not say they wanted to make AoE completely and totally useless in every situation you're likely to ever see. Having done the latter, at least to BM hunters, they've decided to correct the obvious mistake that's at complete odds with the design philosophy they articulated previously of merely wanting to shift focus away from it rather than do away with it entirely.

It's not like they're buffing AoE across the board for every single spec of every single class. They're making AoE more even between all the specs, which is a good thing, because there's quite a few heroic raid encounters with heavy aoe damage requirements.

AoE was tuned down because they didn't want everything to be solved with an AoE spam fest like it was back in Wrath. Maybe they are tunning it back up because they realized two things:

1. There are several situations in both heroics and raids that require AoE and some classes are way ahead of others, to the point some specs are not viable only because of their poor AoE.

2. As people out-gear content, they WILL solve everything with an AoE spam fest, regardless what. It happened at Blood Wing in ICC and it happened now with Cataclysm. Currently, the only heroic I use CCs is Halls of Origination. In every other heroics, including Grim Batol and Deadmines, I just pull everything at once and AoE them down, doing micro-management of my cooldowns, stuns and interrupts to stay alive (I am the tank). I do the same thing in most of Bastion of Twilight too.