It would be fantastic if there could be parts of the game like McMad described. You think the mountain in the distance is just for show but then later in the game you end up finding a way up to it. It would make the world feel more realistic if there were places where you could go just to explore them, even if there's little or nothing there.
One of the things I liked most about WW was the islands dotted about where you could just land and see what was there.