Earlier this year, Valve announced in a rather cool twist that all PlayStation 3 purchases of "Portal 2" would include a Steam copy of the game and that some amount of PC cross-functionality was being built in. Today Valve issued a press release which goes into a little more detail on how the cross-platform stuff will work, which is good timing considering that the game is in stores next week.
"Portal 2" is the first console release to link up in some way with Valve's iTunes-like digital download service for PC (and now Mac as well) games. At the most basic level, built-in Steam support on the PS3 disc offers cross-platform "matchmaking, gameplay, friends, chat and achievements."
Just think, PS3-folk. You get to unlock achievements AND trophies. Oh how jealous your Gamerscore-seeking Xbox buddies will be. What's more, all saved PS3 games will be stored remotely in the Steam Cloud, so you can pick up and keep playing no matter who the console you're using belongs to.
"Portal 2" for PS3 also features a built-in Steam overlay, which presumably resembles the user interface PC gamers see when they fire up the Steam client. From here, you'll be able to track both your PSN and Steam friends, view their status and access other community features like text chat, player profiles, friend requests and game invites.
If you wanted more specific confirmation on the achievements/trophies front, here's what the press release had to say: "Steam Achievements are earned in lockstep with PSN Trophies and are also accessible within the Steam overlay."
Speaking as a dedicated Xbox 360 Gamerscore junkie: jerks.