In the past six months there's been support for new hardware (e.g. AMD Llano Fusion), initial VDPAU work (though this is in a branch), new OpenGL extension support, and support for various new features and functionality (e.g. instanced drawing, unified vertex buffer management). There's even been R600g performance improvements.
Landing just recently in fact to Mesa Git master for the 7.11 release is quite a lot of summer work to R600g. As various readers have noted, there's been a stream of new activity as of late (R600g Git commits). The work in the recent hours and days include various fixes, performance improvements, and more.
Of course, there's new Phoronix benchmarks being worked on at the moment to show off the latest state of Radeon support for Mesa.