nVIDIA ForceWare 100.54 (Vista)
nVIDIA have released some new graphics drivers (32bit can be found here), which include support for the 8800GTS/GTX cards, for Vista. (via Guru3D)
This is amusing, because DirectX 10 is only supported in Vista, and only on the 8xxx series cards from nVIDIA. Can you say oops?
Although not signed and beta drivers, they are more of a resemblence to real drivers than the previous version.
On my computer, the performance increased from 4141 to 4330 in 3DMark06 - small, but I'll take it.