Personally I disagree with what..the's comments. Everyone always says that macs are great for design students. The truth is that both macs and windows pc's are great for all people. The mac is just easier to use than windows, which often suits more creative people who don't want to be held up by computer software.
The advantage of mac hardware is that it's custom selected by apple so that things work better. you don't have issues with drivers and things like you do on windows. the disadvantage of course is that you can't just go anywhere and buy some internal part like you can with a windows desktop, and the apple stuff is also a bit more expensive for buying new stuff.
The greatest thing about the new macs though is the operation system: mac os x. its interface is far superior to windows, in many ways. it's a lot more 'transparent', i,e., you don't get little daft things telling you stuff on the bottom of your screen.
If you live near an Apple Store, then my advise would be to go and try them out. I'm typing this from a macbook pro, and to me the interface makes perfect sense and the switch has been very easy, and I've been a windows user for most of my life.
Games and programs and things will not work. .exe files are a windows things. There are games for macs, but nowhere near as many as on windows. This will be changing more and more, due to the new processors, but it's still a marked difference. As for software: you can get microsoft office, photoshop, illustrator etc. for macs, that work perfectly with their windows equivalents.
http://www.apple.com/switch