NVIDIA GTX 480 and other variants are now working in Hackintosh, there is a thread here on Insanely mac for details of where to find drivers and setup your card.

Here is a card set up in my G5 Hackintosh with 2 x GTX 280's

Audio is not setup correctly yet although is showing up in PCI cards of System Profiler. I need to work out how to inject HDMI Audio as well as the card itself. This may not work correctly until 10.6.5 update.