Valve promised Portal 2 downloadable content this Summer, but has just missed the sunny months, revealing instead that the digital goods will drop in September. It's free though, so quit yer bitching!
No details have been forthcoming about what the DLC might include, with Valve's Doug Lombardi only defending the launch window by claiming, "It's still technically summer." I'm going to guess that the content will include a variety of puzzles that use portals.
Here's a half hour of the Arkham Origins Mr. Freeze DLC, if you want to watch that
11:45 AM on 04.15.2014