Nvidia releases a WHQL GeForce 326.01 drivers. Nvidia didn’t say anything at all about the drivers, or if there is any improvement in performance, but they did put the list of GPUs that is supported by these drivers which is made for desktop (both OEM and retail) and notebook with Nvidia GPU.
They have also put the following message:
NVIDIA released WHQL-certified GeForce drivers today 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.
NVIDIA has long been committed to working with Microsoft to ensure the best possible Windows experience for GeForce users. Our close working relationship with Microsoft allows us to provide WHQL-certified GeForce drivers via Windows Update on Day 1 for key milestones such as this Release Preview.
It’s a substantial effort that requires hundreds of man years of engineering time and thousands of hours of testing and certification, but it’s essential to ensure optimal performance and stability for the world’s largest gaming and productivity platform.