I agree that SE will likely not put in the same level of effort for an VIII remake as VII, but I do feel a remake will happen sooner than later. I imagine VI and even FFX will likely see a remake before it.

I've thought of the idea, and a few months back I posted a thread about how I feel VIII's Junction/Draw mechanics would make it really interesting being re-imagined as an Action RPG. As for other changes, I can see them fleshing out the cast a bit more and perhaps making Ultimecia's motive easier to understand so we can bury this R=U nonsense. Funny enough, Kitase has mentioned in interviews that he did like the "Squall is dead" theory and I can imagine they may add more elements to make you second guess if they actually went along with it.

There is certainly a lot to work with in VIII's scenario and content for expansion and rewrites so a remake would be fascinating.