In a blog post by Intel's Daniel Vetter, he's covered some of the prominent work for this next kernel release.
The biggest change with the Intel kernel graphics driver in Linux 3.7 is the reworked mode-setting code. Aside from that, there's continued work on Haswell, which is Intel's platform for next year. Likewise, there's more work on Valley View for the next-generation Atom SoCs with Intel Ivy Bridge derived graphics.
Some of the other work includes embedded DisplayPort fixes, sysfs support for controlling GPU frequency scaling, and GEM memory management work.
Stay tuned for more information on the Linux 3.7 kernel changes plus, of course, benchmarks.