I'm always amazed by the anti-mac sentiment around here. I got the Mac Pro for working with Photo Mechanic, Aperture and Photoshop. There are a number of things in OS X that facilitate the use of those programs compared to the Windows versions, but accordingly, there are a number of things from Windows I wish OS X had (most notably greater GPU support). I put Vista 64 and the 295 so I can play COD4 and Grid when not working, and to vent steam from work related stress - what's so wrong about that? People apparently just can't get along here.
But back to the topic, OpenCL/CUDA could help speed up chores like the batch processing of raw files I do. Instead of 3-5 hours waiting for my dual core CPU to finish the job, the additional GPU power could shorten that time considerably. I have a 3870 in another computer that is doing nothing but display duty. I would love to put that to raw file processing duty.