Valve have announced upcoming DLC for their acclaimed first-person puzzler Portal 2 will launch on May 8th 2012 and will include a basic map maker and the ability for players to publish and share their creations on Steam Workshop.
The "Perpetual Testing Initiative" allows players to easily create, share, and play Portal 2 puzzles. The Initiative comes with a simplified puzzle maker that allows that creation of mind-bending puzzles without ever leaving the game.
The puzzle maker can directly publish maps to the Steam Workshop where users can browse, vote on, and select to play them. Selected puzzles will automatically be downloaded and installed inside Portal 2.
Unfortunately we don't have any more information than that -- no pretty screenshots or trailers to look at -- so keep an eye on Steam come May 8th.