I must say i don't agree quite with thedeathunter, with the standards of this site, this is all very good considered you only have six posts.
I think the fog in the first and third image is nice, but you should stay away from that radioactive green you're using in the second pic.
Also, in the orc village, you have a very straight cliff close to the camera. Cliffs in real life aren't that steep and sudden.
The high-res cliff is one model that can be used together with the standard UTM models, check out how others (megafyr and raid1000 for example) have used it.
EDIT: For the orc pic, NEVER make your terrain at the edge of the map!!
It looks like the world ends behind the hill!
Go to map options, map size and camera bounds, and increase the bounds behind that hill, then make some less detailed stuff there, some forest or canyons would do fine.