The new Bioshock Infinite DLC was announced today! They announced not one, but two DLCs!
The first is Clash in the Clouds. This is a combat DLC which includes 4 new maps and challenges. It also has a in-game musuem where you can look at character models and behind the scenes content.
The second is story DLC, titled Burial at Sea. It's a detective story set before the downfall of Rapture. It follows a noir styled Booker and Elizabeth and Ken Levine said it's somehow related to the events of Bioshock Infinite. You get to see rapture in it's prime, so that's awesome, it's split into two episodes, episode one you get to play as Booker, and two you play as Elizebeth, which has a survival horror playtype.