I think it's a silly idea because FFVIII, though not as well respected as others in the series, ties up loose ends the best I've seen out of the games. Basically, there's no REASON for there to be a sequel, there's no storyline to build off of for a sequel. I wouldn't want these characters in a totally pointless plot.

A prequel with Laguna would be an ok game, but again, it would have little to nothing to do with the original plot. Yeah, you could see him meet Kiros and Ward, and run around doing silly missions for Galbadia. Perhaps even run around the world as a journalist for a while, but after that, what would you do? What would be your great evil?