While Intel has been working a lot towards OpenGL 3.0 support for their classic DRI driver and core Mesa, they really haven't been focusing upon OpenGL 3.0 support for Gallium3D or those drivers, since it's not part of their offering. However, David Airlie has took it up to begun looking at OpenGL 3.0 support for Gallium3D and specifically how close he can get the Softpipe driver -- the CPU/software-based driver.
He's published a new Mesa branch that betters the Softpipe driver state for GL3 and it's now down to only 220 Piglit regression failures of 7,623 total tests. Some of the missing items include smooth interpolation, cube shadow sampling, integer support, and some GLSL compiler failures.
As far as why David has been working on GL3-Softpipe, "it just seemed like it would be nice to have a reference sw GL3.0 compatible renderer in Mesa 8.0."
Too bad it's not work on LLVMpipe, which is a much faster Gallium3D software driver on modern CPUs due to taking advantage of LLVM for its optimizations, but hopefully that work will come soon. The Nouveau and Radeon Gallium3D drivers also still have a fair amount of work left before being able to advertise proper OpenGL 3.0 / GLSL 1.30 support.
David's Softpipe-GL3 announcement can be found on the mesa-dev list.
In related discussion, it looks like Mesa 8.0 will be branched within the next few days. This major Mesa release was going to be branched today, but it looks like it may be extended until next Wednesday to allow some more work to land before going into stable-bug-fixing mode.
A distribution vendor has been demanding that Mesa 7.12/8.0 be branched ASAP... "the VMware guys *really* want us to make the 8.0 branch today to align with another distro's schedule." and "I talked to said distro and they don't mind doing the branch mid week" etc... They don't mention the distribution by name, but after mentioning the distribution's feature freeze date is 16 February, that means it's Canonical worrying about Ubuntu 12.04 LTS.
Ian Romanick says, "Okay. Eric also talked to them. He was told they wanted a branch soon so that they could start pulling it for their RC builds. Their drop-dead code freeze is February 16th. It seems that branching today or Wednesday and releasing on, say, February 2nd should meet their needs and give us time to fix bugs, etc."
So it looks like Mesa 8.0 will be here in early February! Besides getting close on OpenGL 3.0 support, Mesa 8.0 will also offer up a hell of a lot of other changes. See the many articles about Mesa 7.12-devel, which is what this release has been known as to date. The renaming to Mesa 8.0 comes because of the GL3 work. There's improvements across the board from core Mesa to Gallium3D and its state trackers along with all of the hardware drivers.