For anyone playing world of warcraft who had their framerate drop by a lot after the new 3.3 patch. Check you add ons list because one of them may be screwing around with your FPS. Just disable all on the log on screen, if your framerate goes back to 60, you know its the problem. Then you have to enable them one by one till you find the culprit.
Just a FYI! Now back to some horde killing.