The answer is actually down the page you listed in your post. It's about the software, and support. It says:
"There are two main obstacles to relying on an Apple at GW Law. First, our exam software, Extegrity Exam4, is Windows-only. It also does not work with Virtual PC, a popular software emulation package that is used to run Windows programs on a Mac. Admittedly, taking exams on a notebook computer currently is optional, but it is unclear whether it will remain that way in the future. Second, there may be more curriculum-required software in the future and at the present it is clear that such software will be Windows-based.
Beyond these items (exam software, potential curriculum-required software), it is not so much that Windows is technologically mandatory but rather that our systems are developed in a Windows environment in regards to design, testing, instructions, and support. These include the wired and wireless network authentication and security processes, remote access to the print management system for lasers in the labs, and possibly other services in the future. Success with these services currently may be possible on notebooks with other operating systems such as Macintosh, but students relying on such notebooks will be on their own (i.e., no Help Desk assistance) to achieve compatibility now and they also will be at risk for losing compatibility as our systems develop. The vast majority of our students would not be comfortable with this challenge."
Other than the usual software issue they mention, it's also about minimizing their support costs (theoretically, of course, since they don't give any hard dollars saved by doing this). The hard issues here are that they may be doling out special network access cards, which many corporations use, to validate you beyond just a password. These cards are in wide use in business, as another good way to identify the user. There
are USB versions of these card readers, I have one myself, but the software might not be avaialble to make it work on the Mac. The fact that there is an Active Directory capability in Apple helps, as I bet that they have AD installed (the fact that they are demanding XP Pro instead of Home points to that, Home doesn't support AD) but doesn't get around access cards that don't support the Mac.
Soapbox:
Having run a large support network once, I can say that there is a cost to a business or school, in supporting more than one OS. It requires two experts at least, if not more. Every time you add something like a Cisco environment, someone has to test and support both platforms. One for UNIX/Mac and one for Windows. This might be one person, but as we all know, it's really hard to be really knowledgeable in both. There's a cost to that. A school that is really not a technology school (like MIT for example) might have a hard time justifying that. The other bottom line is that the Mac is just not in wide spread use in business anymore, as a rule. It's niche these days seems to be "creative" types, though I certainly like it's simplicity, interface (which MS is trying to get to with Vista). Unfortunately, People who make these decisions often make blanket judgement calls, like, "the students should use the computers that they will find in the legal world". Sad but true. I've heard it said by execs in my career. If you had a MacBook already, I'd try living with Bootcamp until you hit a wall, then buy the Windows box. If you don't own a Mac yet, and can't afford to be wrong (how much is law school costing you?) then, unfortunately, I would probably opt to get a Windows box. Good luck with law school! It will be hard enough not having to deal with a computer that the campus support folks won't support!
