The first screenshot (above) has a horde of the undead at a bus stop; the same stop which was shown in the last released zombie trailer. Perhaps the bus is an interactive means of transportation?
The second screenshot shows a zombie walking up a broken catwalk. If we were to guess then the map seems to be some abandoned industrial facility.
With the release of the game near, Treyarch has promised a full reveal of the zombie mode tomorrow.
Call of Duty Black Ops 2 is all set for release at the end of October for the PS3, Xbox 360 and PC. The game will be released with the multiplayer undead co-op mode.