Just to confirm (for others who might need to know) – Today’s patch dropped my FPS on my rMBP from 40-60fps to 5-20fps… the SMC reset suggested above returned me to 60fps+
a) Just FYI for those who might have the same problem today.
b) Huge thanks to the folks who discovered it and passed it on! Was afraid I’d have to start booting into wind-blows seven again (shudder).