Mac OS X 10.6 comes with OpenCL, but how many applications could have better performances if they would be rewritten to use OpenCL? What kind of applications should be rewritten to use OpenCL?
My company is using OpenCL for scientific calculations. While I'm not part of the development team which is using it I can tell you a few things they're using it to do: large scale data processing of images, imagine reconstruction, and massively parallelization of previously written scientific code.
Basically, OpenCL is rather cutting edge. Unless you want to/have to deal with it, it's best left for those that need it. I'm not trying to discourage you but it is a niche product designed for a niche market. You'd be better served studying other areas of programming for potential employment purposes.