Sorry for continuing this, but comparing desktops to laptops actually is valid here because while the Mac Pro would be a low end desktop, its still pretty high even for the average user. For the uses of a Mac Pro, a desktop more than suffices with a larger screen, better keyboard, and comfort. The only exclusive niche I can really see for a Mac Pro is if you want something close to a gaming machine that you can carry easily to college. Either way, I'm not saying it for the purpose of trying to beat a laptop with a desktop, I'm just saying that you shouldn't say that it "contends" in the future.
Compared to laptops though, I don't think you can reach the Macbook Pros and maintain that battery life. Thing is though, most people only want laptops for minor tasks, myself included. Still, its interesting how they get that battery life for a desktop CPU with no heatsink.
If Lite Windows XP costs money, careful. I'm pretty sure you need a separate license for both VM and bootcamp, so choose carefully. I'll pretty much list out the differences:
Bootcamp: It'll run like a native PC. That means you need to restart the computer for PC related tasks, but it gets the full benefit of the computer's power.
Virtual Machine: You start it as a program from within OSX, so its much much quicker to swap to PC related tasks. You can multitask between Windows and OSX, but the power available to Windows is much less than bootcamp. One CPU at a time (it doesn't multicore well), half your graphics memory or so, and maybe half the RAM. It'll be fine for SSB64, but for PC games, forget it, even my computer would have some problems running full powered games in a VM.
EDIT: Also, yes, school Macs are POS. I don't usually defend Macs too often, but when people talk about their experience with school Macs, I always try to mention this.