NVIDIA has released ForceWare 101.41 beta drivers for use with Windows Vista.

Release Highlights:

-Beta driver that adds support for NVIDIA SLI support on GeForce 6 and 7 series GPUs
-Improved OpenGL performance
-Improved NVIDIA SLI performance at high resolutions
-General application compatibility fixes
-This driver supports the following features:
-Single GPU support
-DirectX 9 support for GeForce 6/7/8 series GPUs
-DirectX 10 support for GeForce 8800 GPUs
-OpenGL support for GeForce 6/7/8 series GPUs
-NVIDIA SLI support
-DirectX 9 support for GeForce 6/7/8 series GPUs
-OpenGL support for GeForce 6/7/8 series GPUs
-NVIDIA PureVideo HD technology
-DirectX 10 NVIDIA SLI support for GeForce 8800 GPUs will be available in a future driver
-Please read the release notes for more information on product support, feature limitations, and known compatibility issues

Release notes (.pdf format)

Vista 32-bit | Vista 64-bit

NVIDIA homepage