I think that we will all feel that Skyrim is more like a real-place than either Vvardenfell or Cyrodil did, primarily because the new terrain system allows for not just hills, but actual cliffs and overhangs. No more are we traveling over nothing but a series of hills, but now we will see sheer drops and caves.

What varieties of landmass do you wish to see with the new system? Pics are nice for illustrating your wishes.