Seems a few retailers are jumping the gun, advertising materials for a DLC that hasn't even been announced yet. Said materials, seen above, have been spotted at a few different shops, though the source of the pictures (MadAssGamers) didn't say which stores.
As of yet, Activision has yet to confirm the DLC, so take everything here with a grain of salt.
The materials say the new DLC hits April 16th, and offer up the name of four new maps, and a new chapter for the game's zombie mode.
Said maps are Vertigo, Magma, Studio, and Encore. Vertigo is supposedly a remake of a map meant for "Call of Duty: Modern Warfare 2," but which was never released.
As for the Zombie mode, it looks to take place in Alcatraz, the infamous prison. So go watch the Nick Cage movie to get amped up.