@ Bryan, thanks for the advice. I will hold off on an HD 5970 then. Sounds like they just can't hold up to 24/7 crunching well. I suppose that's a lot to ask of any dual GPU, they must run hot hot hot!
I can't understand this AMD dropping CAL/Steam at all. It makes absolutely no sense. By supporting OpenCL only, they sign their own death warrant in the high end computing market where CUDA is already ahead, and they give up valuable advantage to Intel, because Intel's new integrated GPU in Ivy Bridge CPUs will have OpenCL support, and once they get good at implementation, you can be sure it will be downhill for AMD from there.
They were so ahead of NVIDIA on GFLOPS/WATT too, which is uber important in the server arena. Wonder why they are being such pansies and backing out of it all now?