FINAL FANTASY XIII-2 is due out in Japan on December 15, 2011.
Soon after release, Square-Enix plans to release some downloadable add-ons for the title. The contents of those have been shared below:
Original boss monster: Omega.
A familiar monster that has appeared before in the FINAL FANTASY series. Defeating it will let you capture its crystal, which will allow it to become one of your party members.
Additional/Original costume(s) for Noel.
Additional/Original costume(s) for Serah.
These items are intended for the Japanese market. Contents for North America and Europe are yet to be announced.
Full release date and pricing for the DLC is still undetermined, but will come at a later date. We can hope to expect delivery during the months of December and January, however. Also note, that more content will be announced in the future, as this isn’t the full list.