DICE have just released the details for could be the final piece of DLC for Battlefield 3 called 'End Game'

“Battlefield 3: End Game delivers some of the most high-speed warfare to date across four vast maps. Race through enemy lines using the new dirt bike, bringing speed and agility to the Battlefield, or fight back aerial assaults with new lightweight AA vehicles. Coordinate lightning fast attacks and defenses in the return of the classic Capture The Flag game mode. In the skies, the new dropship introduces the ability to turn the tide with rapid deployment air drops of troop transports.”

The new DLC will include

-Four new maps designed for high speed combat and action
-Three new vehicles including the fast and agile dirt bikes
-New dropship provides support to ground troops with vehicle drop capabilities
-Return of the classic Capture The Flag game mode

Currently the DLC is scheduled to be released March 2013.