Windows 8 Release Preview up and running? Check. Nvidia GeForce graphics card? Check. Appropriate GPU drivers for Windows 8? You can check that one off as well, assuming you're running Windows 8 with a GeForce graphics card. If so, Nvidia's new GeForce R302 preview driver is just for you. Bear in mind that it's to be used only with the Win 8 Release Preview build, so if you're rocking an earlier version, these aren't the drivers for you.
There isn't much new that Nvidia's 302.80 driver release brings to the table, and in fact there's only feature highlight in the Release Notes (PDF):
"Windows 8: Updated the Nvidia Control Panel -> Set up stereoscopic 3D page to support Windows 8 implementation of stereoscopic 3D."
There are, however, a handful of open issues that you should be aware of. You may notice flickering in certain instances, for example, or loss of video in Hulu. These and other issues are specific to certain setups and scenarios (see Release Notes).