If I had to make a guess, I would say that the dev team is spending an absolute minimum of time on Warlock class changes. Anything they do to change the class' talents or abilities is going to be completely obliterated in Cataclysm, and we don't have any issues that are critical enough to really need screwing about with. We're good, and we'll remain good until Cataclysm, and then we'll get to find out how to play Warlocks again.