And the best news is that patch 2.3 is likely to show up sooner rather than later. Eyonix, at the very beginning of the big Blue forum rampage yesterday, once again cited voice chat and the new sound system as the reason for the long wait on 2.2. It wasn't a class balance or content patch, it was a completely technical one. And that's why it's been three months since new content. It'll be interesting to see if Blizzard ever tries something technical like this again-- lots of players have asked about upgrading the graphical engine, but if their efforts on the sound engine are any indication, that's just too large an undertaking for them to handle while also being expected to release new content.
But hopefully 2.3 will make up for lost time-- while the coders were working on editing sound channels, hopefully the developers were thinking up new ways to make the classes more powerful and interesting. Of course they haven't announced any release dates (this is Blizzard, after all), but my guess is that we'll see 2.2.2 with a week or two, and 2.3 about a month or so after that, definitely before Christmas.