Straight from the horse’s mouth, Valve is not even bothering with the PS3 anymore. No real reason was given for the lack of PS3 support but one can only assume that it is the disdain Gabe Newell has for the console that lead to this decision.
Keighley: Are you guys working on PlayStation 3 here now, trying to understand it, trying to get better at it?
Gabe: Uh, no. Not in any real way.