NVIDIA has released WHQL-certified GeForce drivers for Windows 8.1 to coincide with the availability of the Windows 8.1 Release Preview from Microsoft.

You can install the new GeForce driver version 326.01 for Windows 8.1 from Windows Update after you install the Release Preview.

The list of supported GeForce GPUs for Windows 8 can be found on NVIDIA.com.

Direct driver links:
Desktop GPUs: GeForce 326.01 for Windows 8.1 Preview 32-bit
Desktop GPUs: GeForce 326.01 for Windows 8.1 Preview 64-bit
Notebook GPUs: GeForce 326.01 for Windows 8.1 Preview 32-bit
Notebook GPUs: GeForce 326.01 for Windows 8.1 Preview 64-bit