I wouldn't look at CS5 at this point. My main complaint there would be ram. Those programs use quite a lot of ram. Scratch disk speed can matter, but it doesn't fully take the place of ram. CS6 seems to be headed toward further gpu reliance more than I would have anticipated. Considering that and Mountain Lion are on the way, I suggest researching that. With CS5 unless you're using the 3d functions in some of the creative suite applications, I wouldn't worry too much as OpenGL can be disabled anyway. It's not that CS5 is really that gpu intensive. It's just that OpenGL functions aren't implemented very well. I don't know if CS6 will still allow it to be disabled given how much they're reworking some of those programs (especially photoshop). Unless you need a machine at the moment I'd wait it out a little while.
