You guys asked for DLC, you got it.
We already knew that Lightning would be a coliseum boss sometime in the near future, but it has been confirmed that she’ll be joining your party at some point as well (presumably after defeating her in said coliseum.) Lightning will have her own secret episode DLC, and other FINAL FANTASY bosses will make their appearance as well.
I suppose this makes up for only playable in the game proper for about 5 minutes… right?
Square Enix also plans the story outside of the game with things such as novels including Sazh, Dajh, and Chocolina.