http://www.digitalspy.co.uk/gaming/news/a280090/square-enix-considering-ffxiii-2.html
There probably going to have to make two sequels. One to explain what the shit happened in the first game and the other to tell this feel good tripe.Final Fantasy XIII could receive a direct sequel, according to its producer.
Yoshinori Kitase said that he wants players to further understand the game's story outside of titles such as Agito XIII and Versus XIII, according to the Ultimania Omega guide for the game (via Andriasang).
When quizzed whether this would mean the release of XIII-2, Kitase said that he is unsure and that it would depend on fan reaction.
He added: "I'd like to at some point make a story where Lightning ends up happy."
The team who worked on XIII have also begun their next project, which will be available within two years.