So far GPGPU, or the ability to use GPU processing power for other tasks than display and rendering, has been essentially evaluated on Pc applications. Christophe Ducommun who offers the excellent shareware MovieGate has started to look into this technology to potentially integrate it in the version 3.0 of its software.
He has published on his blog the result of first tests. While using Core Video, Core Image, OpenGL and QuickTime, he could speed up its encoding from 25 fps when using only the CPU, to 60 fps when dedicating the task to a GeForce 8800 GT installed in a Mac Pro Quad 2.66 GHz. This is really interesting as the performance gain is obtained by only dedicating few tasks to the GPU. Open CL to be introduced with Snow Leopard should further improve such system.
For further information and reading Christophe's report, please follow the link: http://web.me.com/cduco