Portal 2 DLC announced

Valve recently announced DLC for Portal 2. No concrete release date or details have been given as of yet. If I had to take a guess, though, based on the way the game wraps up, it would seem more likely that the DLC would be additional test chambers for the cooperative multiplayer mode, or at the very least a continuation of Atlas and P-Body's story. It could also be that Valve plans to release reworked test chambers much like those that were included in the first Portal. Whatever the case, this announcement isn't terribly surprising, considering the overwhemingly positive response Portal 2 has been getting. What is a pleasant surprise, however, is the fact that the DLC will be free of charge for download on PC, Xbox 360, and PS3.