Resident Evil 6 has at least three more maps for the Mercenaries mode, a score attack mode where you try to shoot as many zombies as you can before time runs out. Capcom has three more maps available for players, but the map you get depends on where you reserve Resident Evil 6.
Rail Yard is a multi-level stage where you shoot zombies and other creatures inside subway cars. You can get this map from Best Buy.
Catacombs has booby traps like spiked floors to watch out for. You can grab this map from Gamestop.
High Seas Fortress is set on an aircraft carrier. The deck is an open area while the hangars inside are narrow. Amazon has this map.
Capcom didn’t say if these maps will be available as downloadable content at a later date, but since other DLC tends to pop up on PSN and XBLA we’re guessing that’s going to be the case. Resident Evil 6 comes out for PS3 and Xbox 360 on October 2.