I really think that the lost woods would be nice, because of how many cool things you could do with wood and the motion plus. also, I would love to have lake hyrule, because this game seems to be rather tropical, and a beach level is perfect for that. the tropical theme might just be the art style fooling me, though
I would love to see the Forest Temple in it's prime! I would LOVE to climb the stairs and spend half an hour running up and down them. Also the Ice Cavern in Zoras Fountain would be cool to see, but not icy... Firey!!!