Itagaki-san confirmed at E3 it won't hit until early 2013 and that they're looking into a release on Nintendo Wii U. It's about '20 to 30 percent' complete.
The actual mechanical side of the game is at 100 percent said Tomonobu Itagaki, but overall it's less than a third done. It's multiplayer is in a playable state and the player count and accuracy is getting worked over by the Valhalla staff.
Devil's Third singleplayer has no co-op and online play is competitive where they're hoping to get 32-players in matches by the end. This September's Tokyo Game Show will spill specifics about what multiplayer modes we can expect.
Devil's Third releases on Xbox 360 and PS3 in early 2013.