Ubuntu Community Council statement on Canonical package licensing

There was an assumption prior to the SteamOS announcement that SteamOS would be based on Ubuntu, based on Valve's previous recommendation to develop Linux games on Ubuntu. Debian was a surprise (and not necessarily a bad one), but no explanation was given for not using Ubuntu, other than it was "for legal reasons."

There was some information on Phoronix about this, but I can't find it. Phoronix must be one of the most self-linking sites on the Internet, which makes it hard to find anything without going around in big circles...