It's actually quite simple...if you're really a good innovative player, you'll find another way to efficiently kill mobs of enemies without mindlessly spamming Fire Storm, Echo, Meteor Shower etc. So for those who have trouble getting over the big bad AoE "nerf," go out there and experiment to find a way. To me, that is my favorite part of the game, experimenting with different skill builds. To help some of you out, here is what I prefer using for my Elementalist:
16 Fire(+4 from Sup Rune & Flame Eye)
12 Energy Storage(Minor Rune)
7-8 Water
1) Immolate
2) Fireball
3) Incendiary Bonds
4) Meteor
5) Glyph of Energy/Renewal(depending on situation)
6) Meteor Shower
7) Aura of Restoration
8) Fire Attunement
Yeah, you'll notice AoE panic if you do the usual spamming of skills that recharge quick. However, try this:
-before the battle, put up #7 & 8.
-Slap #3 on an enemy once they're grouped
-Cast #5, then #6...immediately followed by #4. Meteor knocks them down after the first Meteor Shower hit, long enough for the second hit to land.
They might run away on the third hit, but once they come back, hit 'em with #2 & 3 while your main damage dealers are recharging. Sometimes(depending on the situation) I like to make use of my second profession, and throw in skills like Conjure Phantasm, Phantom Pain, Sympathetic Visage, and other Illusion magic skills. Also another great skill to put in there is Deep Freeze, it'll slow them way down from running from your Meteor Shower.
That's about it, likely the enemies will be long gone at this point. Yeah, go ahead and critique the build, but I've had success with this build, and annoying my teammates with AoE panic has been minimal, so I like it.
So yeah, I agree ArenaNet did hurt the effectiveness of Eles in general, but that by no means they are useless. So instead of telling people how much you hate ArenaNet, go out and experiment with skill builds, and come up with something that works for you
[P.S. just wanted to add in that Mesmers totally rock in PvE groups, I have a build that I've came up with that is great for any situation, which targets the effectiveness of Attackers(W's and R's) and Casters(Mo's, E's, N's and Me's) So if you see me in War Camp spamming the typical LFG's, throw an invite over, you won't be disappointed!

] If you want me to give you my build, whisper me, and I'll gladly give it to ya