If you really want a tablet consider Fujitsu as well.
But a tablet computer is not even in the same class as a MacBook Pro. They don't really compare.
Either will be more then adequate for medical school.
If you want to go the tablet route, you might also consider the HP Elitebook 2740p. I had its predecessor, the 2730p, for a brief while -- as far as tablets go, it's a nice piece of hardware. The slim dock/DVD drive was awesome imo, especially when you have a few external USB devices you want to easily connect at the end of the day.
I'm currently on a 15" MacBook Pro from the 06/2009 refresh, but I'm not "a Mac"; I like Windows 7 / a couple of Linux distros / OS X for their own reasons.
i learned pretty quickly that there is no reason to write on most powerpoints in med school because all the info is there, or in your lecture notes/handouts/assigned readings.
get the macbook
not the pro, just the macbook.
Well, yes and no. OP, if you're a writer when you study -- you like to annotate notes, etc. -- you might be well served by a tablet. Some of my classmates use tablets or go all paper for their notes, and it works well for them, but you do get everything you need to know handed to you in some form or another. It's just a matter of what's most efficient for you in terms of actually knowing it.
If you do choose to get a MB/MBP, I'd vote for getting the MBP flat-out. Yeah, it costs a bit more off the bat, but if you're gonna get a laptop like that, might as well spring for the "pro" unless you really want the base MB. The aluminum unibodies are awesome machines, and the great battery life from the mid-2009 refresh got better with the 04/2010 refresh (see Anandtech's reviews, like
this for the 15" and
this for the 13", FMI).
Oh, and if you're interested in that kind of machine but would rather go with a native Windows laptop, check out the HP Envy 14. Similar aesthetics, but Windows 7 without the handful of quirks you'd get by running Windows 7 under Boot Camp in OS X.