MacOSX has had their Core Image API for a long time which abstracts you from the GPU. Now Adobe has stepped up to the plate by introducing a preview of a new toolkit who's main technology is a new programming language, codenamed "Hydra", that enables the creation of filters and effects that can be compiled down to run on the GPU (if GPU is not available, it falls back to CPU). Here's their tutorial that gives an example of how to write a filter with Hydra. There's also a gallery of sample filters available here. Kudos to Adobe for attempting to bring this technology to the mainstream.
So, the next question is, when are we going to see something similar for WPF and Silverlight? Sure WPF has BitmapEffects, but as anybody who is familiar with the BitmapEffects API knows, they are themselves completely CPU based and, in turn, also force whatever visuals they're applied to be rendered on the CPU. This pretty much renders them a no-no if you're trying to create a really fluid, animated UI... that is as long as you expect to have high frame rates.
People have been asking for this capability since WPF was announced. Where you at Microsoft? :) If only they documented MILCORE, maybe someone could tack it on for them...