Electric Skateboard Firmware Uploaded
The firmware has been made public and can be downloaded as a Mercurial repo on www.bitbucket.com from https://bitbucket.org/gbmhunter/electric-skateboard-firmware.
Note that this is quite a large repo, as it contains the most recent and old versions of code, which were for different platforms.
More information can be found on the Electric Skateboard Firmware page, under Electronics->Projects->Electric Skateboard.