Ian has already published GLX_ARB_create_context for glproto and Mesa, but now he's made public his set of 11 patches for the X.Org Server. For implementing GLX_ARB_create_context, GLX_ARB_create_context_profile, and GLX_EXT_create_context_es2_profile there are 20 patches that go against Mesa and Gallium3D. He published them earlier in the week.
The Mesa-side patches can be found beginning with this email. "This should be the last bit of new functionality necessary for OpenGL 3.0. I'd like to get this reviewed and committed as soon as possible so that we can advertise 3.0 and cut a Mesa 8.0 release branch."
So while OpenGL 3.0 isn't quite there yet, it looks like the next Mesa release will in fact be Mesa 8.0 and not Mesa 7.12.
The 11 patches for the X.Org Server can be found here. Hopefully they will be merged into X.Org Server 1.12, but Keith Packard announced yesterday that the merge window for 1.12 will be closing on Christmas (tomorrow).
GLX_ARB_create_context is the Khronos-approved extension for specifying the OpenGL version and context properties for a new context. This is necessary due to newer OpenGL versions deprecating some features and breaking backwards compatibility in some areas. The registry specification explains: "With the advent of new versions of OpenGL which deprecate features and/or break backward compatibility with older versions, there is a need and desire to indicate at context creation which interface will be used. These extensions add a new context creation routine with attributes specifying the GL version and context properties requested for the context, and additionally add an attribute specifying the GL profile requested for a context of OpenGL 3.2 or later. It also allows making an OpenGL 3.0 or later context current without providing a default framebuffer."
Finally OpenGL 3.0 support is nearing the light of day in the open-source Linux graphics drivers, nearly three years after the Khronos Group released the specification.