Right now dubbed "Portal 2 DLC #1" (why would they name it #1 if we weren't getting more?), the summer-bound downloadable content will include "new test chambers for players, leaderboards, challenge mode for single and multiplayer modes, and more." I wonder what "more" could mean?
As mentioned yesterday, the downloadable content released for Portal was simply a collection of more test chambers. In that pack, the story didn't continue, there was no further interaction with GlaDOS. There's a larger cast of characters to play around with in Portal 2, so perhaps "more" ties into them.
I've asked Valve if we can expect any new narrative in the add-on, but have yet to hear back.
Even better, you won't pay a dime for this. The content will be free across every platform Portal 2 is available on--PlayStation 3, PC, Mac and Xbox 360. Valve's desire to distribute free content post-release has been a point of contention with Microsoft in the past (see: the lack of updates for Team Fortress 2 after The Orange Box was released), but that's not standing in the way of more testing. Onward to science.
Nice of Valve to release it for free too, they're certainly good at building user gratification.
cool!