But the CMs are sharing some info about why the patch is so delayed. The main culprit seems to be the voice chat system, and more than that, the fact that Blizzard completely updated their sound engine while including it. Blizzard, like many other companies, didn't write their own sound engine for WoW. They licensed one called FMOD, by a company called Firelight (the same engine used in Bioshock, Metroid Prime 3, Heavenly Sword, Crysis, and many other games). Firelight just released a new version of FMOD-- their website mentions 4.08 as the latest, though I'm not sure that's the exact version Blizzard is using in 2.2 (Blizzard may be a version behind, just to make sure there are no problems with the system before they push it out to all 9 million clients). 4.08 also just dropped a few days ago, it seems, but maybe Blizzard, as one of Firelight's biggest customers, had access to the new version before anyone else did.
At any rate, that's why 2.2 is taking so much longer-- they're working on code, not class balance. Hopefully, whenever we do see this patch drop, it'll sound that much better.