Okay...why don't you game on your PC? (I mean I understand playing lots of systems, not just PC, that's what I do, but...) And why did you get a 4890 if you don't play games?
Good GPUs do accelerate more and more other stuff, but like Folding @ Home runs better on Nvidia GPUs (not that ATi users shouldn't do it too! I think it's just the architecture, not all ATi's cores are identical, and I suspect only 1 in 5 is actually useful for Folding, while all of Nvidia's more uniform cores are probably useful for it-I mean ATi's hardware still does fast, useful work though!), and there's more GPU programs on the Nvidia sidei.