It would be interesting to see the special items Link got throughout the game. I'd expect things like the hookshot and Master Sword return, but things like the bow would probably get some sort of futuristic replacement. As for the city, it would probably be built around the castle as normal, perhaps with the castle unaltered and used as a bit of a monument to Hylian history. Also, it would be pretty awesome if Link rode a motorcycle instead of a horse. Motorbike-back combat would be the best addition to any game ever.