http://beyond3d.com/content/news/735
NVIDIA have released certified OpenCL drivers for Windows and Linux, after passing conformance tests at Khronos in June. The Windows version is available for XP, Vista and 7, both 32- and 64-bit in all cases, and is tagged 190.89 for driver version number spotters.
The Linux one is 190.29 and is available for 32- and 64-bit just like the Windows version. Both OSes get support for the visual profiler, and any CUDA-capable GPU is an OpenCL compatible one, from G80 all the way up, and including Tesla T10-powered hardware in the compute space too.