To see what it would be like on next gen consoles. I would be interested to see what they improve/fix/expand/etc in the game with new hardware, might return to its roots like in Fable 1, among other things.
I don't want another Fable 3, but a Fable 4 that takes full advantage of next gen hardware sounds interesting and has potential.
I see another painfully boring shallow rpg... with prettier graphics. I would say any RPG has as much potential as a fable sequel.