The multiple discs of FFVII contained the entire game each, it was the FMV and other assets that took up the discs, going back to an older sections didn't require you to change the discs.
I think they are going to fold in some of the other stories they have added to the game since then and make some of the other sections of the story longer. Hopefully they make Sepheroth a decent boss this time I was largely disappointed in the final fight with him after all the build up. I remember specifically leveling up for the fight remembering how the Kafka fight was at the end. When I finally went there hoping I was ready, it was the most disappointing few moment in my life. (3 moves he didn't even get anything non-scripted in)
And as for those hoping for it earily next year, it will not be ready. By senerio it usually only means the outline of the game. But it looks far along so we may see it in the second half of the year.
