Valve has announced (via Destructoid) that the next free update for Portal 2 will include the Perpetual Testing Initiative, which is fancy Aperture-talk for what we in the shamefully Portal-poor world call “a level editor.” The PTI update, due for release as a free Steam download come May 8, will add a finalized version of the simplified map editor that saw beta-testing last year.
Maps created within the Perpetual Testing Initiative will be available for sharing on the Steam Workshop (in case you'd gotten this far on hope and fumes, it should be clarified for definite that the PTI content's bound only for computer players). Valve's also said that some maps will get bundled into the game itself, though presumably that initial idea you had for a map shaped exactly like Mario's head might need a little fine-tuning if it'll make the cut.
