Mass Effect 3's "Extended Cut" DLC, which builds on the game's controversial ending to hopefully give unsatisfied fans some closure, is now available on Xbox Live, PSN, and PC. The extended cut does not replace any of the content from the original version of the game's ending.
Separately, Skyrim fans should also know that the game's first expansion pack, Dawnguard, is now available on Xbox Live. Dawnguard is a timed exclusive for Xbox 360, but will come to other platforms in the future.