2v2 balance has always been a pure mess, and if they try to balance the game around that the other aspects would suffer too much from it. WoW was simply not made with 2v2 arena PvP in mind, if you want that to work well you basicly need a completely different game with homogenized classes. I like Cataclysm PvP way more than WotLK, overall it's less bursty, it had new battlegrounds based on tried-and-true concepts that were actually fun as opposed to Strand/Isle, along with the addition of rated BGs so arenas is not the only "real" way of PvP progression.
I disagree, Cataclysm PvP was a disaster in my opinion. It started off nice enough, but my class (Warrior) was ruined. (I understand 2v2 svcks btw, was just an example.)
The RBG fiasco is what eventually made me quit. They were a nice change at the start, but soon became a major crapfest, WSG and TP was all about stacking healers on your Prot Warrior while BfG was all about AoEing the flags. To make it worse Alliance had a terrible headstart in BfG which made it hell for Horde players, especially if you're up against Hydramist and the likes of that.
My guild and I facerolled to 2400 without any effort or rating loss whatsoever due to the crappy MMR system, then I got bored while lots of my guildies went on to easily achieve the top 0.5% thingie.
But this I could live with, I'm not petty enough to dismiss it because it makes gearing "easier" (there was still a major time investment) like a lot of people. It just started getting terrible in S10, where you
HAD to do RBGs every week to get your full conquest points cap. This is something I simply didn't want to do, I was fed up with the relatively bad state of RBGs after playing a few hundred over all characters in S9.
The new BGs were pretty much the only good part about Cata PvP. Sure, they weren't exactly new, but WSG and AB have always been the kings of all BGs, and I played a few thousand of both those.
However the balance was long gone even in the most balanced bracket, 3v3. Remember KFC? Jesus that was a major disaster. Then TSG made its major comeback, it was simply hop on the bandwagon or enjoy a headache and Rival title...

I still spent a good amount of time hanging around Warcraftmovies and AJ after I quit to see if things would improve, but seeing setups with 2 mages and 2 rogues kill people in a matter of seconds convinced me it was no longer worth it.