I just made the first successful LWJGL OpenCL call, yay. I should be able to implement OpenCL 1.0, 1.1 + extensions over the weekend, then I'll work on the java-side API, then integration with OpenGL... should have a beta version committed by the next weekend, hopefully.
It took a while because OpenCL makes heavy use of pointer arrays and size_t parameters. I ended up implementing a PointerBuffer class that mirrors the LongBuffer API at the Java-side, but works with either 32bit or 64bit values underneath. Then I had to add support for it in our generator, do a bit of refactoring, etc.