Of the three expansions for Battlefield 3, this impending one, Armored Kill, is finally the one to make me regret not sticking with the core game. Take a look at this launch trailer, which really drives the point home by primarily letting the gameplay speak for itself. This is exactly what I want to get out of Battlefield.
Armored Kill is currently available for download on PlayStation 3 if you are Battlefield 3 Premium member and it will be ready for PC and Xbox 360 on September 11, 2012. For non-members, you'll unfortunately have to wait until Sept. 18 on PS3 and Sept. 25 on PC and Xbox 360. In the latter case, be sure to have $14.99 to spend on this content if you're interested.
To recap, the expansion includes six new vehicles, four maps -- including the self-proclaimed largest map in Battlefield history -- Tank Superiority mode, and additional unlocks to keep you playing.