i just finished my first year of law school with a mac, and I had very few complaints. here are a couple points:
first, about 10-15% of my class uses a mac. my school is not mac-friendly when it comes to exams, but to me, it's worth it.
someone has already mentioned http://www.maclawstudents.com
and i second that. it's a great site that i used to find nice software. also, it has an okay list of what schools do or do not support macs.
bottom line for me is this: i'm a mac guy and I think they're better computers for all kinds of reasons. i decided that it was worth it. I had 8 finals my first year (four per semester) at about 3-4 hours each. let's say i spent 30 hours taking exams versus 5,000,000,000,000 hours studying through those semesters. on my mac.
even if they don't support it, it's worth it to not have to fight with windows.
also- i was lucky enough to commandeer my wife's windows laptop for exams, but i found out that the requirements are VERY modest, and I knew a couple of people who bought old crappy laptops for $100 that used exam software. you can check that out too.
hope that helps.
also- i know you're all worried about law school and what to do and what to study and how to prepare. my advice to you: read "One L" by Scott Turow and nothing else. Enjoy your last summer of freedom; make some money. I bought Planet Law School and read about 2 pages. I spent 40-50 hours researching how to be a law student and made a 100 page book of tips, tricks, and hints that I NEVER LOOKED AT AGAIN. "One L" is the most accurate account of law school you'll see. Just know that when you get to school, nobody will know what they're doing, and the people that spent a bunch of money on preparing won't know what to do either. you just have to get in it to figure it out. it's not about learning tricks. it's about changing the way you think. enjoy your last days of freedom. you'll read enough next semester.