Skyrim is one of the smallest areas we got to jump around in yet. I know it's much to ask but as developers get better at making games, how cool would it not be to get a game with parts of or WHOLE Tamirel?
Just think.. Running from one side of Skyrim to the other takes an hour of ingame time (and sure a lot of stuff is thrown there)
Map of the whole world: http://www.tes.altervista.org/mappagigante.jpg