I'm not so sure it's the laptop as it is the software. Apple's own offerings are awesome. GarageBand, Logic, etc. are cool, plus you can still do ProTools.
On top of that, if you get MacBook Pro and there's one or two apps that are only for Windows that you think you might need... well, the Mac does Windows too.
I think it's a win/win situation with the MacBook. Plus, since it is a Mac, when you're dealing with other music gurus, there's a good chance they'll also be using a Mac as well.
I'd say the MacBook Pro is probably the best.