Support for the SuperAudioBoard has been accepted into the official Raspberry Pi kernel fork, and is now included as part of the bleeding edge 'rpi-update' release.  It will eventually be included in the official Raspbian image, but I don't know the timing of these releases.

Configuring a Raspberry Pi to work with the SuperAudioBoard is now as simple as updating the latest image of Raspbian using the 'rpi-update' command, and making some changes to the /boot/config.txt (see the user guide for details).