I'm sure quite a lot of stuff is broken and so forth, but I can honestly say that I have yet to experience any post 3.0.8 issues at all. Everything that I do in particular works fine, which is mostly heroics and dailies at this point. I don't do WG, battlegrounds, raiding, etc, so that doesn't affect me.

In fact, since WotLK was released, the only bug that has affected me at all is the random lag in northrend when WG is up, aside from that I have yet to experience any bugs or issues.