Ian Romanick of Intel released Mesa 10.0 Release Candidate 2 on Saturday for any last minute testing. He's hope to declare the Mesa 10.0 release on Wednesday, 27 November, unless any other major last-minute issues are encountered.
The rather bare Mesa 10.0 RC2 message can be read on the Mesa-dev list.
Mesa 10.0 brings many new features and provides GPU OpenGL performance improvements. It's a very exciting three-month update to Mesa and is the first that ships with core Mesa support in full for the OpenGL 3.2 and 3.3 extensions, but the only hardware driver taking full advantage of those GL extensions and GLSL capabilities is the Intel DRI driver for Ivy Bridge and Haswell hardware.