Xbox 360 owners will find the Rebellion DLC pack available for download in Mass Effect 3 right now. The Rebellion pack is free to those who have activated their Online Pass and adds a new objective type, two new maps, and three new playable characters to the multiplayer side of BioWare's latest RPG.
PC and PS3 owners will have to wait for Rebellion. Chris Priestly, BioWare's community guy, says that it'll be available on those platforms "soon." We'll be sure to update as soon as BioWare reveals new details.