For those of you who want even more of Commander Sheppard, EA has answered your fevered fan cries and has announced upcoming DLC for Mass Effect 3.
Leviathan, both the name of the DLC and the name of the ship you are hunting, features a rogue reaper that Sheppard must track down. There'll be more characters, planets and plenty of background about the origins of the Reapers.
Expected to launch sometime this summer; keep your eyes peeled for further details.