EA has clarified that maps featured in the upcoming 'Back to Karkand' DLC for Battlefield 3 will be "part of the same rotation as the base maps" once the content becomes available. A tweet this morning from the official Battlefield account, which was since been deleted, originally stated that the DLC maps would only be playable in a "separate map rotation," much like Bad Company 2's 'Vietnam' DLC.
EA confirmed the original message was incorrect to Joystiq. When asked if future downloadable content would follow the same policy, EA noted that it has yet to announce details for future DLC and it currently focused on launching the Karkand content.
Battlefield 3's homage DLC 'Back to Karkand' launches in December and features four "classic" maps from Battlefield 2. Though the content will be made available for $15 when it launches, it will be made available for free to users that ordered Battlefield 3 prior to its October 25 launch date.
[Image of the original Tweet available from Joystiq]