The more important point is there is finally a Open standard for GPGPU, CUDA and Stream are both FTL.
Hardware exclusive API are stopping technology from advancing.
nVidia is ahead in slightly the GPGPU field while ATi is ahead in hardware Tessllation, after so many years we can finally get away from the "will my card support OOXX?" mess.
EDIT: OpenCL, or any open standard for that matter, is good for the market but not necesarily for the advancement of technology. I'm not saying we don't need open standards, but I don't agree at all with that propietary tech must die for the good of all. Both aproaches can coexist and developers are smart enough to know which is better for them and their consumers.
EDIT2: Sorry for all the edits, but I want to make this point clear. IMO propietary tech must die eventually, but it has to die by choice of the consumers (in this case developers) and not the companies behind those technologies. For example, I know for sure that GPGPU is here and is as strong as it is right now thanks to CUDA and only CUDA. If Nvidia had stopped pushing CUDA when OpenCL was first mentioned, first, OpenCL would have never been develped that fast and second the adoption of GPGPU wouldn't be as pronounced as it is and the future and viability for such a technology would still be under the question mark. In the last 3 years a lot of developers have learned how to program in GPUs thanks to CUDA. CUDA and OpenCL (and Stream and DX compute) are very similar in how you have to program for them, so CUDA did 90% of the travel. In no way that has held technology back, on the contrary it has moved it ahead more than what it would have advanced if we would have been waiting until an open standard was developed.
CUDA and Stream are going nowhere, not in the short term. Both companies use wrappers to run OpenCL so performance is going to be slightly lower. Small developers (game developers included) will prabably use OpenCL (or DX compute) for the most part so that it can run on any hardware, but big players (think
ORLN or
Cray) will use CUDA/Stream, at least until GPU's ISAs mirror OpenCL in their silicon.
OpenCL/Compute will be no different from Direct3D in that the biggest part of the games are going to be coded with them, but developers slightly concerned about performance and optimization will always write some critical stuff in CUDA/Stream, just like they write some stuff in HLSL.
Finally, let's put things into perspective, right now Nvidia is far ahead of AMD when it comes to GPGPU and it will probably stay like that for almost the entire 2010. You simply can't compare the adoption rate of both solutions, the available tools to each and the functionality/strength of said tools. It's just like night and day ATM.