It has been officially confirmed by DICE that the four maps that will make up the first Battlefield 4 DLC pack while the expansion pack four BF3 maps also which have been redesigned using the Frosbite 3 engine. The confirmed maps are: Operation Firestorm, Operation Metro, Caspian Border and Gulf of Oman.
The news was also confirmed by Microsoft at a Battlefield 4 Xbox Live event. DICE has emphasised that BF3 maps that make up Second Assault will be advanced and enhanced to include new multiplayer features from Battlefield 4.
The game will release in the summer of 2014 and EA has also confirmed about its availability at launch first on Xbox one.