I think a game which deals with the bit in the middle would be cool ie. inbetween the time frame of the Laguna flashbacks and the actual game. It could show how Laguna came to be president, his marriage to Raine, why he gave up Squall (if he was his father) and all the jazz. It would have to take place over a rather long time period though probably.

I don't think they will ever do anything with VIII though because there are considerably less loose ends than there were in VII (which had mysteries and annoying things they left undone by the BUCKET load). With VIII they leave it up to you to work out what you think will or had happened. Which is the way I like it franckly.