Valve: First Portal 2 DLC to be free
Valve has always kept an active trend of making DLC free (well mainly for the PC) they made all the class updates for Team Fortress 2 free, Free DLC for Left 4 Dead 1 and 2 and they revamped Counter Strike: Source completely for free while the DLC's did cost MSP on the XBOX 360 Valve has decided to give their DLC a whole new direction on the consoles and release them for free on the consoles too.
Portal 2 is one of their BIGGEST successes yet and is definitely a contender for the game of the year award, scoring an average of 9.0/10 with many acclaimed gaming sites the game is definitely going places. Although valve hasn't mentioned the date of the new DLC valve has made it certain that there will definitely be a lot of DLC for the game. (just look at the class updates of TF 2 and DLC maps for L4D / 2 if you want proof of Valve's dedication to DLC)