From a reliable source at the company, I have been told at least one of their very popular titles will see a release for Ubuntu Linux this calendar year. I was told this in person and was a statement backed up by additional proof. With their first Linux port they will use it to judge the waters of Linux gaming themselves to decide their future course. This port is being done internally by their own developers, which isn't a huge surprise given their past public statements and already existing internal Linux client work.