I have MacBook 11 and dual-boot with Linux Mint 14. It runs great, much prefer it over OS X. If there was one thing I could steal from OS X though it would be the trackpad and multitouch implementation. On all the distros I have installed it sucks, it is truly awful. This is the only real deal breaker holding me back from using Linux primarily on the Air at the moment, I am not going to carry a mouse around.
At the moment I use a debian VM inside OS X when I need to.