This looks to me like a publicity stunt since ATI's original GPGPU offering was a flop. Nvidia's OpenCL SDK actually works on their graphics cards though it is in limited beta last I checked.
Not to mention that you can compile CUDA code in "emulation" mode for execution on the CPU, too. The utility is largely for debugging, because the CPU is darned slow executing it, so I'm not sure it has any use in production.
I think that's just their way of making sure they don't lose track of where their possibly still very buggy software goes so that they can get the feedback and tell their users when it's time to upgrade.
The differences with CUDA are so small though that it is fine to develop for CUDA now and upgrade to OpenCL when they release it publicly.
