Besides the first piece of DLC (which is just a horde mode) out today called Clash in the Clouds there will be two story based episodes out later where you play in Rapture called Burial at Sea. Burial at Sea will be set one day before Rapture's collapse, and the entire story arc will be told in two episodes. The overall experience will be improved by having better gameplay, and Levine says that this DLC will have new Vigors/Plasmids, the sky-lines, Big Daddies, and more. In Burial at Sea you will also be able to play as Elizabeth. Clash of the Clouds will cost $4.99 and each episode of Burial at Sea will be $14.99. You can get all the DLC by buying the season pass for $19.99.
PlayStation 4 reserves 3.5GB of its 8GB GDDR5 memory for the operating system, leaving 4.5GB of space for game code, according to current PlayStation 4 documentation shown to Digital Foundry by a well-placed development source. However, further sources suggest that an additional 1GB of "flexible memory" may be reclaimed from the OS reservation, based on availability. Read the entire story at Eurogamer.
Xbox One = 3GB OS and 5GB for games.
Playstation 4 = 3.5GB OS and 4.5-5.5GB for games because of "flexible" memory.