Today, Battlefield revealed the theme for the Final Stand DLC slated to release later this Fall. Final Stand will be the last (scheduled) DLC package of Battlefield 4 (there has been some speculation of a pack of re-imagined maps, but it has been no more than a rumor to date).
Final Stand will take place in snowy Russia, and the fiction involves scientists working on experimental weapons. One map is said to include a battle pick-up that will be a rail gun firing powerful bursts of kinetic energy. In the trailer released today, the map Operation Whiteout is shown to include the prototype hover tank. The Battlefield Blog post states that players will discover these prototype weapons and vehicles, which makes me wonder if the hover tank will be unlocked via capturing a point (expect that capture point to get a lot of action as everyone fights to get their chance at the tank). The DLC will include four new maps, shown briefly in the trailer: Operation Whiteout, Hammerhead, Giants of Karelia, and Hangar 21. One of these last two maps included a glimpse of what appeared to be mech suits, so expect those to be either a battle pick-up/capture point vehicle, or a grand tease of Battlefield 2143.
Premium players on PC have the option of joining the Community Test Environment (CTE), where they will have the opportunity to help test the Final Stand DLC to ensure a clean launch. Battlefield will start running servers that include the Final Stand maps today, September 9. It is not clear for how long Final Stand maps will be available on the CTE prior to launch of the DLC.