NVIDIA just posted their newest beta drivers this morning. They tell us that the 304.48 drivers boost performance by up to 18 percent in games like Batman: Arkham City, Dragon Age, II and Battlefield 3. Their tests, done with the GTX 680, pushed performance up 17.6 percent in Arkham City, 12.4 percent in Dragon Age 2 and even Lost Planet 2 saw a boost of 4 percent.
You don't need the best card to get a boost from this update, though. NVIDIA (test results) says that the GeForce 400, 500, and 600 series cards will all see faster frame rates in popular titles.
There are also Control Panel game enhancements, adding MSAA support to Diablo III (pictured above, full comparison here), Rayman Origins, L.A. Noire and The Secret World, as well as ambient occlusion support to Star Wars: The Old Republic. Add in updated profiles for SLI and 3D vision as well as some single-GPU issue fixes adnd you have a must-download.