Valve announced that next month, Steam is coming to Mac OSX, with native compatibility with all Valve games.
Added features such as Steam Cloud and the SDK development kits will also be available from launch, showing Valve´s firm support for the platform.
As an extra bonus, the Left 4 Dead games will support cross platform play, meaning that PC and Mac players will be able to compete and assist each other in matches.
The recently announced Portal 2 has also been chosen as the first simultaneous release on both platforms.