With everything we thought we knew about the "Back to Karkand" expansion for Battlefield 3, we were surprised when the official @Battlefield Twitter noted (since deleted) the DLC would be "a separate map rotation," like the Vietnam expansion for Battlefield: Bad Company 2.
EA informs us the official message from the company was incorrect. The PR director for Battlefield 3 told Joystiq, "Back to Karkand maps will be part of the same rotation as the base maps."
We asked if this would hold true for all future Battlefield 3 DLC, but were informed the company hasn't announced details for future DLC and is currently focused on launching Karkand. The Back to Karkand content will be available sometime in December for $15, or free to those who pre-ordered the Limited Edition copy of the game.