Valve announced today that the second add-on for Portal 2 is coming out in 2012. The update will add on an "easy-to-use in-game map editor that will let users design, build and share their own single-player and co-op test chambers with the community." Effectively, this means that knowledge of the Source engine is no longer required to make custom maps.

Additionally, players will be able to play and rate other players levels. It's supposed to be easy, taking only a "single click."For now, the editor has only been announced for PC, but we've reached out to Valve to find out if it will come to other platforms. This update follows the recently released "Peer Review" DLC, which we checked out earlier this month