I am currently awaiting my MacBook Pro (en route as we speak.) I'm a junior biology major.
I would have waited for a rev B, but frankly I could wait. My PC laptop died several months back (2 batterys worn out in 3 years, 2 cd-rw/dvd drive failures, and 2 loud chipping screaming hard drive failures.) I've been limiting by on a unstable desktop PC, the other day it rebooted itself 4 times in 5 hours. Anyways it put me in the market for a new computer. Friends and family all have apples in one shape or form, so I limped by on a horrible desktop for months, because I knew apple was going to introduce intel within the year and had read the rumors that there would be intels in jan, so I waited. Then I argued with myself over and over back and forth between toshiba and apple. What pused me over the edge, those 2 failed hard drives were toshibas.
As I don't have an apple at the moment, I can't comment of the quailty of the macbook pro for you.
As for the PC vs Laptop. So far everyone is right, you can do perfectly fine with a desktop in college (hauling a thumb drive around), yes the desktop is cheaper, the desktop will be more powerful in most cases, and if you are in college then there is a good chance when you get out you will need a specific software (which may require a new computer or a PC even.)
I picked a laptop for a bunch of reason, but size and portability were the main two. A laptop takes up less space, which is at a premumium in a dorm (or a cluttered apartment like mine.) I travel, dpending on the GF's schedule I spend 50-100% of my weekends out of town (she has a laptop, but its a dull and we both need them over the weekend for school work.) And when I got home, well its a free for all, my sister has a thinkpad (when she is home) my parents have a gateway and both are always in use. Even around my apartment the laptop gets used as a mobile, either in bed before I sleep, out side on a nice day, at the desk to do papers and school work and in my lap to run things like aim while I am watching TV.
Sorry if this made no sense its kind of late for me and I'm having trouble putting my into words.
Cliffnotes: If you can wait to make sure that are no flaws in the macbook pro, then wait, just to be safe. As for laptop vs desktop, its just a matter of lifestyle and needs, I travel and need a computer that can go with me, plus i hate being anchored to a desk.