The Linux 3.1 kernel is out, Phoronix discusses the new features of this release over here. It includes better support for Intel's Sandy Bridge integrated graphics as well as preliminary support for the upcoming Ivy Bridge CPUs.
LLC, the feature that enables the Sandy Bridge graphics to use the CPU cache, is now enabled by default for this latest generation of Intel processors. The LLC patches have been floating around since March, but now they are mainline and found in the Linux 3.1 kernel. The LLC work is responsible for much of the performance improvements in Linux 3.1. LLC will also be possible for Intel Ivy Bridge CPUs.
While it is not going to improve the performance like LLC, frame-buffer compression (FBC) for Gen6 (Sandy Bridge) is now on by default and will help extend your battery life. Compressing the frame-buffer results in less data needing to be transferred upon screen refreshes and as a result less memory bandwidth is needed, which can result in a small power savings. FBC is disabled by default on pre-Gen6 hardware due to outstanding bugs, but it can be manually enabled by setting the kernel command line option of i915.i915_enable_fbc=1. Frame-buffer compression is finally enabled by default for Sandy Bridge graphics now that various improvements have been made.