I'm currently running Archlinux on a Macbook air. The instructions in that wiki article were rather confusing. I had to fiddle around quite a bit to get the EFI boot manager to work. The wireless driver is shit cause the MBA uses a Broadcom card. The version in the latest stable kernel actually segfaults and crashes the OS when you try to use a WPA2 network. Also, I still can't get the audio capture to work in ALSA.

In general, there is very little to reason to buy a Macbook if you want a capable Linux laptop. I only have an MBA because my company gave it to me. Better to buy a similarly-priced Thinkpad and use that.