EA announced that they planned to delay a "key" project outside of the 2013 fiscal year during their financial call yesterday. The popular consensus, according to analyst Michael Pachter and Kotaku, at least, is that the game in question is most likely Dragon Age III.
According to EA, the mystery game was delayed because members of its team were re-purposed to help work on a different project. According to Pachter, that information means that the game in question had be coming from Bioware: Specifically, that Dragon Age III developers were shifted off the project to work on Star Wars: The Old Republic.
Kotaku's Stephen Totilo conceded that Pachter's theory could be correct, but asserted that the Dragon Age III staff changed gears to help work on Mass Effect 3 instead. You could argue that the Mass Effect 3 team needs more help, since they've been tasked with producing that extra ending content as quickly as possible, while minimizing the delays on the game's DLC.
Either way, both of them think Dragon Age III is the mystery game. EA has said publicly that the game is development, and Bioware held a panel on the future of the Dragon Age franchise at PAX East last month. That said, little information about the game itself has come to light, so the idea that it might be pushed back to later in 2013 doesn't seem particularly unreasonable.