As of yet, only Nvidia's desktop graphics cards are supported, as drivers for the mobile GeForce series are still under development. The Windows 8 desktop PC R302 drivers can be downloaded from Nvidia's website (32-bit and 64-bit), and are supported in Windows 8 alone. The software provides full support to the new Windows Display Driver Model (WDDM) 1.2 and also allows Nvidia's 3D Vision technology to be used.
AMD's drivers can also be downloaded already and do offer support for mobile graphics cards. At the time of writing, AMD's Eyefinity, OpenCL, OpenGL, UVD, CrossFire, AMD Overdrive and the Catalyst Control Center are fully supported. The power consumption has also been decreased and cards will provide a video output sooner when switching from standby. As is to be expected, the software for both manufacturers does have some bugs still.