The Guru of 3D posted new GeForce Forceware 275.27 beta drivers. Use them at your own risk.

New GeForce Beta drivers are available. This is GeForce Forceware 275.27 for all GeForce 6, 7, 8, 9, 100, 200, 300, 400 and series 500 cards to date. We have a discussion thread open on this driver right here

GeForce GTX 580:

Up to 4% in Crysis 2
Up to 5% in Civilization V with SLI
Up to 9% in Portal 2
Up to 13% in Bulletstorm with Antialiasing enabled
Up to 15% in Batman: Arkham Asylum with PhysX High
GeForce GTX 560:

Up to 6% in Crysis 2
Up to 8% in Portal 2
Up to 14% in Batman: Arkham Asylum with PhysX High
Up to 15% in Bulletstorm with Antialiasing enabled
Increases gaming performance by up to 12% for dual-core CPUs in CPU-limited cases.

NVIDIA Update

In Release 275, NVIDIA Update adds automatic SLI, multi-GPU, and antialiasing (AA) profile updates. These profile updates are automatically downloaded from NVIDIA and silently installed on your PC, keeping it up-to-the-minute with the latest game profiles. When you install a Release 270 or later GeForce driver from www.nvidia.com, you will be presented with the option to install NVIDIA Update. Click here to learn more about NVIDIA Update.
Desktop Scaling

New NVIDIA Control Panel user interface for configuring desktop scaling, including new preview window.
Now consistently available for all displays (including VGA and HDMI connections).
New scaling override option for Windows 7 gaming.
Improved desktop resizing user interface that guides the user to disable overscanning using their HDTV controls and also provides a fallback option to enable desktop resizing via the NVIDIA Control panel.
NVIDIA desktop resizing now creates a custom, resized resolution with 1:1 pixel mapping and resizes standard resolutions for games that don’t support custom resolutions.
NVIDIA 3D Vision

With Release 275 drivers, the 3D Vision Controller driver is now included with all GPU driver installations. This driver package includes v275.22 3D Vision Controller driver. Users are no longer required to install a separate 3D Vision Controller driver or CD driver. For more information, please view this knowledgebase article for more information.
3D Vision Window Mode support. Please view this knowledgebase article for more information.
Added support for 3D Vision Photo viewer to now work in Window Mode. When you have opened a 3D picture file check the “View” section for this new option.
Improved 3D Vision IR emitter and 3D Vision glasses synchronization
Adds support for new 3D Vision projectors: NEC NP-V300X series
Added the following 3D Vision game profiles:
Age of Empires Online
Assassin's Creed Brotherhood
Battlefield Play4Free
Duke Nukem Forever
Dungeon Siege III
Super Street Fighter IV
World of Tanks
Update the following 3D Vision game profiles
Portal 2 – fixed water reflection problem and updated convergence setting to provide a better user experience
The Witcher 2 – Improved 3D Vision compatibility for all in-game effects

GeForce Forceware 275.27 Win XP x32
GeForce Forceware 275.27 Win 7 Vista x64
GeForce Forceware 275.27 Win 7 Vista x32