It looks like Nvidia is slowly but steadily abandoning OpenCL – their OpenCL examples are not included in the 5.0 SDK anymore and the links on their OpenCL webpage are dead. It is not clear if this is an oversight or intentional. With the recent introduction of the Intel Xeon Phi, an accelerator that supports OpenCL, this could be a strategic move on Nvidia’s part.
I’ve created a github repository that contains all Nvidia OpenCL examples from CUDA version 4.2.9. Please note that it currently contains only the Linux examples. Feel free to fork and add the Windows and Mac OS examples.