Mesa 7.9, one of the biggest updates to this open-source graphics driver stack in quite a while, is almost here. Ian Romanick has made available a release candidate for Mesa 7.9 and is saying the final release will be here one week from now (4 October) barring any major issues cropping up.
Mesa 7.9 brings many improvements from support for new OpenGL extensions and a brand new GLSL compiler to a ton of improvements to the individual classic DRI drivers and especially when it comes to the Gallium3D architecture and its drivers and state trackers. See this Phoronix search page
for more details on the massive changes to be found within Mesa 7.9.
The very brief announcement of Mesa 7.9 RC1 can be found on the mesa-announce list