NVIDIA released the GeForce 178.13 drivers, you can grab them over here. Here's a look at the changelog, the driver features several performance improvements in single-GPU and SLI configurations:
WHQL-certified driver for GeForce 6-series, 7-series, 8-series, 9-series,
and 200-series GPUs, including the newly released GeForce
9800 GTX+, 9800
GT, 9500 GT,
Adds support for NVIDIA PhysX
acceleration on all GeForce 8-series, 9-series and 200-series GPUs with a
minimum of 256MB dedicated graphics memory (this driver package installs NVIDIA
PhysX System Software v8.09.04).
Experience GPU PhysX acceleration in several full games and demos today by
Adds support for 2-way NVIDIA SLI technology with GeForce GTX 200-series
GPUs on Intel® D5400XS motherboards.