OpenGL 3.0 is already supported with mesa from git master and the upcoming 3.4 kernel. Hiz support is almost complete and OpenCL support is already working for basic test apps.
PCIe2 support (and upcoming 3) would also be nice. What's holding that up - is it certain card/motherboard combos that are buggy, or are there entire families of cards causing problems? It certainly seems to be close.