On a german page called www.play3.de there was a news right today about EPIC GAMES having a new IP launching in 2014. A new coop game, a trilogy, too. It is rumoured that if you play alone, the second character is controller by the intellegence of the console. Setting is said to be postapocalyptic.
Maybe PS4 exclusive?! Search for Project Nano/Blueprint.
http://www.play3.de/2013/11/07/epic-games-angeblich-neue-koop-action-trilogie-in-entwicklung-project-nanoblueprint/
*of course, handle it like a rumour, just sayin'