I'll still stand by that the original phoronix posts were inaccurate and misleading, and at the very least deserving of apology. Nothing was confirmed back then, none of the so-called release timeframes were proper, and the dead horse was beaten for about 2 years. Even now, all that's shown are some desktops - something I rather suspected Valve to do internally, but still nothing indicative of official support. No actual quotes from Newell himself. Nothing official. UT3 was more official than all this at one point, and look how that turned out.
The point is: until Valve themselves issue a press release, nothing's official. Take everything here with a massive haul pack load of salt. The best you can take from it is that Valve have games running on linux desktops internally within the company. Anything more is pure speculation, and really should be labelled as such within any posts.