have you run into any problems with the built-in wireless? i know the older powerpc based models did not have a linux driver available for the wireless, but i'm not familiar with the intels.
The wireless works fine for me. I think I've come across a post or two on forums about the newest MacBooks having issues with the wireless that force people to use ndiswrapper, but mine works fine. I wouldn't suggest getting a Mac if you know you're going to be running Linux all the time. I got mine because I got a pretty nice discount. I never touch the OS X partition.