"Since I expect Windows 8 to be strongly dotNET-based, I think OpenCL and CUDA will have a real confrontation with DirectCompute not earlier 2012/2013. GPU-vendors to support their technique when they can sell more hardware, but it will take a while until GPGPU is adopted on Windows. Another reason
"If I were Microsoft, I would change DirectCompute to be able to load OpenCL-kernels natively and focus on easy initialisation and good integration. Such decision would attract more developers to Windows, Visual Studio, dotNET than the current approach."