Valve has all but confirmed rumors that it plans to bring its Steam gaming platform to Mac OS X systems. In a clever teaser campaign yesterday, the company began sending gamer blogs It seems likely that all of these titles will make their way to Mac systems along with the Steam client. What's more, this might be an indication that Valve has ported their Source game engine over to OS X, which would allow any future games based on this engine to be easily launched for the Mac. A formal announcement is expected during the 2010 Game Developers Conference, scheduled for next week, from March 9th to the 13th.