About the desktop/laptop issue, tbw,
i'm definitely going to buy a laptop in august, mainly because i like to have the option of being...how should i put it, technologically mobile? if you plan to use the computers in the PBL room, the library, or your room, then it's probably not worth it to have a laptop, but if you'd like to bring your computer to other places (starbucks, your other friends' libraries, friends' apartments or dorms, home, etc) and do research, get one. I don't know how much med students actually use computers, probably a lot more at cornell than non-PBL places...
...i have an awesome desktop right now (relatively) and I'm probably going to bring that to school, too, but i haven't decided yet...Olin is pretty small and a laptop conveniently allows you more desk space when you need it, or just space in general...
not very insightful, but they're my thoughts nonetheless...