Are you saying that Gallium has OpenCL now? As far as I can tell the GPGPU acceleration currently depends on the closed source proprietary drivers provided by the vendors (nVidia, AMD), even on Linux.
Well, OpenCL is an open standard, but implementations are obviously proprietary.
If you're just talking about shaders, well I don't find them so exciting, at least when considering the monster cards such as Fermi. If hardly makes a difference if you can render your game in 60fps versus 600fps.
One thing to remember is that OpenCL is merely a different programming interface to the same shader hardware (admittedly a much more convenient one and one that's becoming increasingly specialised) that regular shader programs use. Many compute tasks have actually been implemented using nothing more than basic GLSL.
It's gone now, but fractal.io (
video here) was a fantastic demonstration of what can be achieved with nothing more than opengl shaders.
