I uh, dunno. Nothing big. A few set of outfits for the X-2 girls to wear outside of battle, I guess. Same with FFX.

Oh, I know. A side mission in FFX. A "Rikku's story" mode that took place between when you first meet her on the boat, and when you mess up the party later with that machina thing. Come to think of it, Lulu's failed pilgrimage could have been a nice DLC thing too. It'd have to be thoroughly done, of course. No cheap-and-easy money grab.