With Portal 2 just around the corner, Valve has just released a Question and Answer for Portal 2 and everything you need to know about the PlayStation 3 version.
Valve also released the first official screenshots of Steam working on the PS3. They show that people will be able to access the Steam overlay by pressing the SELECT button while Portal 2 is playing.
Some features that this will bring along is the chance to play cross-platform from the PlayStation 3 to the Windows or Mac version of the game. You'll also be able to play with Steam friends and redeem DLC, which is registered on other versions of Steam.
The Q&A also answers a few questions like linking your PSN account with your Steam account, accessing the free Windows and Mac version which comes with the PlayStation 3 version, and using the Steam Cloud on the PlayStation 3.
You can find the lengthy Q&A in the source provided. Portal 2 comes out the 19th of April in North America and the 21st of April in Europe and Australia.