If you do get the video card(8800GTX) it can be used almost for anything, since it is a TOP of the line gaming/graphics card(not including Quadro's here). As everyone who plays alot of 3D games knows, if  a video card can play the newest games at a high resolution(1280x1024 and up with AA/AF high frame rates etc..), then it can very easly do any graphic apps. 

I was just reading into the fact,  you want to do graphics, and the faster your processor ,the more detail in less time you can output(any type of app). But Vista is almost here for retail, and that graphics card can run DirectX 10 apps and functions, so that is another thing to consider if you need those. It comes down to preference and cost to most.