*walks around like a lost child who's wandered to far from her ff6 forums..*
I don't see why we'd need the spoilers but this is my take.
(SPOILER)Remember when Tidus jumped off the thing, all that nonsense, if you watch past the credits after Suteki Da Ne playing and what not, it shows him in a fetal type position in water, Square-enix has most likely done that, so when they made FFX-2, they could bring him back. It's the only thing that showed that there's the possibility of him being alive.
But if you don't get the perfect ending does that mean they drowned him? :p
*walks off looking around for familiar things*