A new WHQL driver hit the web, this is revision 197.77 WHQL which carries support for pretty much any GeForce graphics cards in the series GeForce 6000 and upwards to series 200. Apparantly the GTX 400 series does not have proper support. The first reports are that these drivers run extremely well.
We do not have release notes just yet but we do have an open and active discussion thread live right here.