I'm really disappointed there wasn't more information on what he was running, this is something I'd love to set up on my own, with or without the Rasperry Pi.
This is the related code: https://github.com/albertz/shairport/
snos has the correct link above, from the beginning of the video, it looks like he's running airplay-nmt: http://code.google.com/p/airplay-nmt/