This week Bioware announced an official release date for its first single-player downloadable content (DLC) for Mass Effect 3 (as long as you don't count day-1 DLC or the Extended Cut fiasco). Mass Effect 3 Leviathan will be released on August 28th for PS3, Xbox 360, and PC. For Playstation 3 owners in Europe, though, the content will be a day late and arrive on August 29th.
Bioware earlier this month released details about what players can expect from the Leviathan DLC. From the Bioware blog:
Something lurks in the dark corners of space, something powerful enough to kill a Reaper. Shepard must discover the most closely guarded secret in the galaxy before the Reapers silence it forever. Discover more about the origins of the Reapers as you race across the galaxy to find the Leviathan. Unravel the dark history of the Reaper Race before it is too late. Coming later this summer there is no war, only the harvest.
Later in that blog post Bioware states that the Leviathan is actually a "mysterious being," though they don't hint at what its power might be. In terms of where the new DLC fits into the Mass Effect cannon, Bioware said that Leviathan is set during the events of Mass Effect 3, so don't expect the Leviathan's power to be galaxy-altering.
The Leviathan DLC will cost $10 if purchased for the PC or via the PlayStation Network, or 800 Microsoft Points if purchased through Xbox LIVE.
The DLC will also unlock new star systems and Citadel areas for players to explore, new characters to speak with, and two new weapons: the AT-12 Raider Shotgun and the M-55 Argus Assault Rifle. If players want even more new weapons, they can now purchase the Firefight Pack DLC weapon pack, which was released last week. The weapon pack is for single-player only and costs $2 for the PC and Playstation Network, or 160 Microsoft Points through Xbox LIVE.