Gears of War: Judgement is currently in development by Epic Games and People Can Fly, the latter of which developed the 2011 shooter Bulletstorm. The story takes place before the core Gears of War trilogy and does not follow the exploits of Marcus Fenix. This game follows the trial of Damon Baird, Augustus 'Cole Train' Cole and the rest of Kilo Squad. The exact circumstances of the trial haven't been made clear, but we know that the Squad is on trial for desertion, cowardice, theft of military tech among other things.
We're pretty excited for Gears of War: Judgement and while March 2013 seems pretty far away, we didn't even know that Gears of War: Judgement existed just a couple months back, so there's always that.