In a new email by Denis he proposes working on replacing Mesa IR with GLSL IR. This has been expressed before as a possible GSoC project.
Marek Olšák has responded to say that Intel may already be working on this effort of gutting Mesa IR and to replace it with the GL Shading Language IR. Marek ended up suggesting just working on a Gallium3D hardware driver this summer.
Simultaneously, there's also the work under-way already on using LLVM IR for Mesa / Gallium3D via the LunarGLASS project.
In related news, the latest S3TC effort for Mesa whereby Mesa would simply provide support for passing pre-compiled S3TC compressed textures to the GPU but not do any any compress/decompression itself due to patents, has also been rejected. The basis is that Mesa cannot even provide this binary S3TC texture pass-through support since although most modern GPUs have the hardware support in place, the vendors may need to hold a license for open-source Linux driver support too from S3 Graphics. As a result, even this limited implementation would still be legally problematic in the US, Europe, and Japan. This was explained by Jose Fonseca.