Personally, I'm BM and MM right now, rolling as MM for most fights. The SV rotation is extremely focus starved and clunky at the moment, though its aoe brings happy numbers. BM, in it's own right, suffers on movement fights or switches, where it can be difficult to time your kill commands with pet movement. :( I'm really enjoying the MM rotation though. http://bit.ly/hT4bfn

Blizzard has had the attitude that all specs do not need to perform equally, and this is the problem. Especially in most raiding guilds where you are expected to spec the most optimal way, hell many guilds will not take you if they think you have enchanted or gemed wrong.
http://bit.ly/ethIZf