AMD's Tom Stellard has published the latest series of patches for bringing up the GPGPU compute infrastructure in their open-source R600 Gallium3D driver.
The latest R600g Compute patches can be found on the Mesa-dev mailing list
These latest patches won't enable OpenCL/Compute within the driver for end-users, but is a prerequisite for that ultimate milestone. Other recent work includes merging the LLVM shader compiler
and the Clover work getting ready