Although there is very little information about these maps, I have found this out:
Location- Unknown
Terrain - Forerunner
Wraparound is an upcoming multiplayer map that will be featured in Halo 4. It is set in a Forerunner environment. It is now confirmed that Wraparound is a forerunner power facilty used to generate the artificial sun inside the Forerunner legendary planet. It is confirmed that the map is not a remake of an old map, but is completely new. This map will focus on verticality and height-based gameplay. The ViDoc hints the presence of Gravity Lifts on the maps as Spartan IV are seen being propelled across the map and this is confirmed in the 3/21/12 version of the Halo Bulletin.
Location - In orbit above unidentified gas giant
Terrain - Civilian manufacturing plant
Warhouse is an upcoming multiplayer map for Halo 4. It is set in a civilian manufacturing plant that is traveling in a near space orbit above a gas giant, with a large mech being constructed in the middle of it. Not much else is known about it at this point.This map focuses on close quarters combat due to the presence of corridors and rooms in a small map. The mech in the middle of the map is what looks like a new version of the Cyclops from Halo WarsThe mech is in a platform similar to the one found in the map Condemned in the Halo: Reach Defiant map pack