The BioShock Infinite website announces Clash in the Clouds, a DLC pack for BioShock Infinite that will start rolling out today, though they say it may take a few days to reach all platforms and regions. This trailer shows off the pack, and here's the description: "This first add-on pack puts an intense focus on BioShock Infinite combat. Combine weapons, Vigors, Gear, Tears, and Sky-Lines in ways you never thought possible as you square off against impossible odds. This pack features 60 challenges in four brand-new environments. Complete Blue Ribbon Challenges and unlock concept art, Voxophones, Kinetoscopes, and more in The Columbian Archeological Society. Climb the Leaderboards and earn new Achievements and Trophies." In a separate announcement, Irrational Games also reveals BioShock Infinite: Burial at Sea - Episode 1, a DLC featuring Booker and (post-jailbait) Elizabeth adventuring around Rapture, the underwater setting of the original BioShock. This is shown off in this trailer, and word is: "this DLC features Rapture as you’ve never seen it before—a shining jewel at the bottom of the ocean, built almost entirely from scratch in the BioShock Infinite engine. Gameplay has been modified to give the player an original BioShock combat experience that merges the best parts of BioShock and BioShock Infinite: new weapons, new Plasmids/Vigors, Tears, Sky-Lines, and Big Daddies." There's an interview on Eurogamer.net where Ken Levine fills in more details, saying the Burial at Sea DLC takes place in 1958, and that the second part will include the ability to play as Elizabeth. This announcement has the release details:

BioShock Infinite: Clash in the Clouds is available starting today for £3.69 (400 Microsoft Points on Xbox Live® for Xbox 360) via online marketplaces on all available platforms, and is included in the BioShock Infinite Season Pass*.

Also in development at Irrational Games, BioShock Infinite: Burial at Sea* is a two-part add-on campaign featuring an all-new story for Booker and Elizabeth, set in the underwater city of Rapture before its fall. These two campaigns will be available individually for £9.99 (1200 Microsoft Points), and are also included as part of the BioShock Infinite Season Pass.