Around 40 games are being supported initially: see www. But it seems to be slow work, with only an older XP driver for cards up to the GeForce7-series at launch. Mid-December should see a Vista and 8800-series driver, and also a fix to some of the more noticeable 3D issues. Text, for example, needs to be displayed in 2D to be readable, and in-game head-up displays can jar the effect and look out of place in the 3D world.
There are also issues with performance. With two different images being beamed out to your eyes, the frame rate understandably takes a pounding.