Apparently some form of community functionality will be attached to player creations, allowing other users to "view, play, and vote" on various levels. Outside of some cursory details -- the editor will allow players to create and share both single-player and co-op levels -- little is known about how editing will work, or if the DLC will arrive on both PC/Mac and consoles.
With Steam support on all but one console, the Xbox 360, we wouldn't be surprised if the second Portal 2 DLC doesn't arrive everywhere. But then Valve head Gabe Newell indicated differently in a recent interview, so we just can't be sure. We've reached out to Valve for some clarity.
Valve Announces Portal 2 Update Featuring In-Game Editor
October 21, 2011 - Valve, creators of best-selling game franchises (such as Half-Life, Left 4 Dead, Team Fortress, and Counter-Strike) and leading technologies (such as Steam and Source), today announced the second game add-on for the year's highest rated multiplatform game, Portal 2, is in development and targeted for release early next year.
This major update will feature 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, who will be able to view, play and vote on them with a simple click.
Portal 2 was released April 19, and currently holds a Metacritic score of 95%, making it the top-rated multiplatform game of 2011. Its first content update, "Peer Review", came out two weeks ago.
A hilariously mind-bending adventure that challenges you to use wits over weaponry in a funhouse of diabolical science, Portal 2 features expansive single and cooperative multiplayer game modes. For more information on Portal 2 and its downloadable content, please visit http://www.thinkwithportals.com.