DICE has released a short teaser trailer for the Battlefield 4 Naval Strike DLC. The DLC is will be the third out of five scheduled expansions, with China Rising and Second Assault out now.
Naval Strike will feature four new multiplayer maps set in the South China Sea, a new amphibious hovercraft, and a new mode called Carrier Assault, which is actually a re-imagining of Battlefield 2142‘s Titan Mode.
https://www.youtube.com/watch?v=I7jgn-yABCw
Naval Strike will be released later this month for Battlefield 4 Premium members and will roll out to all players at a later date.