I'd like to see more interesting geographic features, mesas in particular.
They would be scattered about in sandy, windy parts of the map, especially deserts and wastelands. A mesa would add an advantage to a biome normally overlooked because of its harshness in the form of an awesome tower-like fort that stacks around a dozen layers over the surface.
I could see it being very doable, since all of the conditions for natural structures like these are hard-coded into the game already. They'd pretty much be an inverted chasm.
What do you guys think?
http://en.wikipedia.org/wiki/ButteAnd shut up, it was an awesome joke