In addition to playable teasers of Saga Frontier 2 and IS Internal Section and movies of four other games (including Cyberborg and Chocobo Racing) the disc will feature data for several Square titles (an exact list is unannounced) which can be downloaded to memory card. This data can then be used to boost character states, unlock hidden items, and more.
Square will release Chocobo's Mysterious Dungeon 2 on December 23 in Japan. There are currently no plans to bring the title stateside. Kudos to Magic Box for the heads up on this story.