Well, the OS X 10.8.3 update is finally out, and the big news is the diverse new graphics support. Apple's added drivers for some AMD Radeon HD 7xxx graphics cards to OS X. There are a few tricks required for enabling these cards, so we're not recommending them officially yet.
OS X 10.8.3 devices supported:
AMD Radeon HD 7750, 7770, 7870, 7950, 7970
The AMD Radeon HD 7xxx must be the secondary graphics device in your system in order to boot using Chimera/Chameleon without a boot error and gibberish text.