In an interesting, albeit spoiler-ridden interview with key members of Portal 2’s design team at Fast Company, Valve’s VP of marketing Doug Lombardi announces the future announcement of DLC for the game. At the moment, hard details are scarce though as many of you probably know, there is plenty of backstory that was divulged in the Portal “Lab Rat” comic as well as the strange ARG leading up to the game’s release that wasn’t actually touched on in the game. In addition, there’s the tangential connection to the Half-Life 2 universe that has never been fully explored in the Portal games. Suffice to say there is much more to the universe that they can build gameplay around, up to and including adding more challenge rooms with a de-emphasis on story or additional co-op courses. At any rate, I can totally go for more Portal. Expect the DLC to launch this Summer.
UPDATE: According to Patrick Klepek over at GiantBomb, the aforementioned DLC will A) predominantly consist of new test chambers and challenge rooms, seemingly akin to those post-completion challenges found in the first game and B) will be free of charge. Good news abounds.