I was just going to say that there is very little chance that we won't have at least some big CGI cutscenes, as that's an FF staple, and they are usually FAR beyond what current consoles can manage (including some of the trailer stuff we've seen already).
I think there's certainly room for improving compression levels with different codecs, rates, and so on.
Scooby, as far as I remember, a lot of recent Final Fantasies offered you the ability to visit different areas you've been to already at leisure, to find secret items and monsters, replay certain 'mini' games, and so on. FFX-2 was even more extreme in that you had a lot of stuff you could do in different areas in whatever order you wanted. I'm not sure how FFXII is, as I didn't get too far into the game.
Regardless of that - 4 disc swapping in a 60 hour RPG doesn't have to be an issue, no, but it's still a matter of perception. It's been there already of course for two other big releases on the 360, but they were early in the game and weren't multi-platform. By the time FFXIII releases, which is, what, 2010, and it is released simultaneously with a lot of press, then it's going to bring the issue of space on a DVD vs BluRay (further) into the limelight. Never mind whether it is perfectly possible to play the game on 4 discs, it will show that the BluRay space is there for games, something which even games that currently use the BD quite strongly (like currently Uncharted and MGS4) won't achieve directly. People will see some great graphics, maybe, and a meaty game, and great sound, but they won't immediately think 'that's because of BluRay!'. In that sense, something like a high-profile multi-platform release is much more acute. I'm willing to bet that by this time Microsoft has worked something out with SE for partial HDD installation though.