The Guru of 3D posted ForceWare 257.15 beta drivers for Windows 7 and Windows XP. Use them at your own risk.

NVIDIA has released the first series 257 drivers, this is revision 257.15 BETA which carries support for a large amount of GeForce graphics cards.

The 257.15 beta driver includes the PhysX 9.10.0222 system software, the HD audio 1.0.9.1 driver, and has support for GeForce 6, 7, 8, 9, 100, 200, 300 and 400 (GTX 465 too) series desktop cards, and the ION GPUs.

Adds support for Blu-ray 3D with NVIDIA 3D Vision technology.
Increases performance for GeForce GTX 400 Series GPUs in several PC games. 4 example:
Up to 14% in Aliens vs. Predator (1920x1200 noAA/AF – Tessellation on)
Up to 4% in Batman: Arkham Asylum (1920x1200 4xAA/16xAF PhysX=High)
Up to 5% in BattleForge (1920x1200 4xAA/16xAF – Very High settings)
Up to 5% in Call of Duty: Modern Warfare 2 (1920x1200 4xAA/16xAF)
Up to 4% in Crysis: Warhead (1920x1200 4xAA/16xAF – Enthusiast setting)
Up to 24% in Enemy Territory: Quake Wars (1920x1200 no AA/AF)
Up to 9% in Far Cry 2 (2560x1600 8xAA/16xAF)
Up to 25% in Just Cause 2 (2560x1600 no AA/AF - Concrete Jungle)
Up to 7% in Metro 2033 (1920x1200 no AA/16xAF – Tessellation on)
Up to 40% in Metro 2033 with SLI ((1920x1200 4xAA/16xAF – Tessellation on)
Up to 8% in S.T.A.L.K.E.R.: Call of Pripyat (1920x1200 no AA/AF – Day)
Up to 110% in Stone Giant with SLI (2650x1600 – Tessellation on, DoF on)
Up to 6% in The Chronicles of Riddick: Dark Athena (2560x1600 no AA/AF)
Up to 9% in Unigine: Tropics (2560x1600 no AA/AF – OpenGL)
Up to 5% in 3DMark Vantage (Performance and Extreme Presets)
Up to 19% with Transparency AA (1920x1200 4xTrSS – measured in Crysis)
Adds support for OpenGL 4.0 for GeForce GTX 400 Series GPUs.
Adds support for CUDA Toolkit 3.1 which includes significant performance increases for double precision math operations.
Adds support for new extreme Antialiasing modes for 3-way SLI PCs, including up to SLI48x AA for GeForce 200 series GPUs and up to SLI96x AA for GeForce GTX 400 series GPUs.
Adds support for a new ‘Quality’ mode for NVIDIA’s Ambient Occlusion control panel feature.
Adds a new Nvidia Control Panel setup page for SLI and PhysX for ultimate control over multi-gpu configurations.
Adds a new Nvidia Control Panel feature for ultimate control over CUDA GPUs, allowing the user to effectively choose which GPU will power each CUDA application.
Includes numerous bug fixes.
A specific change log will follow later on.

ForceWare 257.15 Win 7 | Vista 64-bit Beta download from Guru3D.com
ForceWare 257.15 Win 7 | Vista 32-bit Beta download from Guru3D.com
ForceWare 257.15 Windows XP 32-bit Beta download from Guru3D.com