Advice for college: go for portability over power. You should still try to get a Core 2 Duo, I'd say, but go for a small screen (maybe 14") and the lightest model you can find. I have a workhorse, and I never take it anywhere because it's too heavy and just a bother to carry. My roommate's 3 lb. Vaio, on the other hand, goes anywhere.

I'd definitely shell out the cash to get a sleek unit, if I were to do it over again.