I just gave it a quick run "1 hour" and seem to work well with my 2xGTX480's..
Post how it works for you. Thanks.

Release Highlights: 295.51 Beta January 31, 2012

This is the first beta release from the R295 family of drivers. For more information, read the 295.51 driver article on GeForce.com.

This driver package supports GeForce 6, 7, 8, 9, 100, 200, 300, 400, and 500-series desktop GPUs as well as ION desktop GPUs.

New in 295.51

NVIDIA SLI

Adds or updates SLI profiles for :
7554
Kingdoms of Amalur: Reckoning
Mass Effect 3
Oil Rush
Red Faction: Armageddon

3D Vision

Adds support for 3D Vision windowed mode on DLP HDTVs and on Optimized for GeForce passive 3D monitors
Adds or updates 3D Vision profiles for:
The Adventures of Tintin – rated Good
Afterfall: Insanity – rated Fair
Black Prophecy – rated Not Recommended
Chaos Online – rated Fair
Da Vinci Online – rated Fair
DotA 2 – rating upgraded to Fair
Dungeon and Dragons: Daggerdale – rated Fair
Ferrari Project – rated Not Recommended
The First Templar – rated Fair
Fractal – rated Excellent
FreeStyle 2 – rated Good
The Haunted Halls Reach – rated Excellent
King Arthur II – rated Not Recommended
Kingdoms of Amalur: Reckoning – rated Fair
Kong Fu Ying Xiong – rated Fair
Love Beat – rated Good
Marvel Super Hero Squad Online – rated Good
Microsoft Flight – rated Fair
Perpetuum – rated Fair
Post Apocalyptic Mayhem – rated Fair
Prototype 2 – rated Fair
Q.U.B.E. – rated Excellent
Quan Qiu Shi Ming – rated Excellent
rFactor 2 (mod mode) – rated Good
Saints Row: The Third – Rated Not Recommended
Shadow Company: Left for Dead – rated Not Recommended
Special Force – Rated Good
Tera – rated Good
Top Gun: Hard Lock – rated Not Recommended
Tropico 4 – rated Good
Worms Blast – rated Good

NVIDIA PhysX

Updates PhysX System Software to 9.11.1111

HD Audio

Updates HD Audio to version 1.3.12.0

Key Bug Fixes and Enhancements

Fixes instances where the GeForce GTX 590 fan unnecessarily increased to 100%.
Fixes instances of driver timeouts while simultaneously watching multiple videos.
Adds edit/delete option for custom resolutions.

Other Details

Supports multiple languages and APIs for GPU computing: CUDA C, CUDA C++, CUDA Fortran, OpenCL, DirectCompute, and Microsoft C++ AMP.
Supports single GPU and NVIDIA SLI technology on DirectX 9, DirectX 10, DirectX 11, and OpenGL, including 3-way SLI, Quad SLI, and SLI support on SLI-certified Intel and AMD motherboards.

Link: http://www.nvidia.com/Download/Find.aspx?lang=en-us

This driver has failed for me in folding@home. I guessing its the driver since I didn't have any problems with either of the other 2 beta's before it.
Anyway I'm rolling back to 290.53 beta for now. It could have been bad work units or heat since it was pretty warm here today.
But for now I think I'll roll back to see if there are still stability problems while folding@home. I found both my 480's had stopped folding.

Edit: Haven't ever had this problem before. If its not stable enough to fold then its not for me. Ya nothing to do with gaming I know, but I did
see one problem while playing rage today. The game hung for about 30 seconds, witch it has never done. I thought it was locked up
but it went back to working after the 30 seconds. So I'm thinking this is video driver related too.

Update: just so you now there could be problems with this driver.

I am seeing one problem I wasn't before the 1.2 update now.
Anytime I get into a car my frame rate drops to 30 FPS, where before it was always 60 fps no matter what I was doing.
I have changed drivers, but had problems with those and went back to what I was using, but its still there 30 fps.
I did raise all new added video settings to max, but it was still 60 fps no matter what with 290.53 driver.
I updated to 295.xx is when the problem started, I did a clean install back to 290.xx and the problem remains.
The game is still very much playable even at 30 fps, but was much smoother at the 60 fps.
So I'm not sure if its the patch or driver related. I did notice it updated the cuda driver, but didn't see where it downgraded when I when back to 290.xx.
So there could be a problem in the new cuda driver. This is on the Desktop rig in my sig.
I thought at the time folding@home was the only thing having problems, but I also installed the 295 driver on a rig with a GTX260 and it had
problems folding stable as well.

It is a BETA driver, after all. Problems are to be expected.

Ya I knew this before installing I was only trying to give feed back on what I found so far.
I had no problems like these with the other two beta drivers before it.
290.36 had a problem with driver has quit responding when coming out of a game or when quitting folding.
This problem seem to be fixed in the 290.53 beta, so I was hoping they had made more imrpovements in this release 295.51.
At this point its looking like they went backwards and created more problems. I had hoped Nvidia would released a WHQL driver this go round.