I think its a good start, but I'll throw some comments out too...
1) Its a little monotone, you might try varying the colors on the different levels of terrain. However if that was your intent then don't worry about it.
2) You might try putting a pit of noise & gaussian blur on the roads to help them blend into the terrain, unless they are supposed to be elevated.
Keep going and post updates often, let's see where you can take it.