Update: current efforts are focused on Cloo (object-oriented CL wrapper), which can be found here. It provides a much cleaner OpenCL API compared to raw bindings (which are also available in case you need them).
The generator now supports generating C# OpenCL wrappers from the C headers. The OpenCL wrappers reside under the OpenTK.Compute.CL10 namespace of SVN trunk. An OpenCL sample has also been added to Examples.exe: if you have access to an OpenCL implementation, please run the VectorAdd sample and report your results here.
AMD has released a public beta of its OpenCL implementation that you can download from AMD's developer website (free registration needed). This implementation runs on all SSE3-capable CPUs and is available for Window and Linux platforms.
There is a lot of fine-tuning left to do for OpenTK's OpenCL wrappers and the sooner you test the bindings, the sooner they will become ready for release.