I installed 64bit Windows 7, I just tossed in my Snow Leopard CD and installed the Bootcamp drivers from that. Sound works, Magic Mouse works, OFP: Dragon Rising plays well. I do seem to be getting an issue with Bluetooth where the mouse/keyboard connection are dropped, but that's not such a big problem as the MM and bluetooth keyboard suck for gaming anyway.
You just need to disable "allow windows to shut off bluetooth to conserve power" in the devices section.