I'd recommend against it. Get a small, light laptop (Apple PowerBook 12", Dell 700m, Alienware 233 or similar). Everybody I know that bought a heavy laptop doesn't take it to class. If you're not going to bring it with you, just buy a desktop.
Remember, casebooks are heavy. Filling your backpack/courier bag with 30# books and 10# of laptop, and you'll have a chiropractor on speed dial.
If you need to, you can attach a larger monitor and full size keyboard at home, but I've become used to the small size.