Seems like its mostly bug and performance fixes, but heres what they state are the release highlights:
You can get the full list of changes here (for the win2k/xp version): http://download.nvidia.com/Windows/53.03/F...nXP2k_53.03.pdfIncreased graphics performance when using nForce3 systems.
Improved HDTV Y Pr Pb component out support for 480i, 480p, 720p, and 1080i formats*
Added support for GeForce 5900 XT
Microsoft® DirectX® and OpenGL® support
NVIDIA nView 3.0 Multi-display technology