If you’re going to be a CIS major you’ll want a good PC. Visual Studio is a resource HOG. If this is your career path and you can’t afford a real good PC you should probably sell the Mac and use that money to get a real good PC.
Good example, my dev box here at work has 3 gig of ram, and my laptop is a 2ghz pmobile with a gig of ram. VS 2005 Pro is much happier on my desktop, but runs ok on the laptop.