All in all, a worthy effort. You can see the RobA tutorial influence, but with a good dose of your own style. The main weakness, IMO, is the mountains (also the most difficult part to get right, also IMHO). The first issue I notice with your mountains is that their color is the exact same as the background color of the map layers below the bumpmap. I think I know why you did that (with some of the mountains overlapping into desert regions, and the like), but they might look better if there was some sort of mountain-color layer with a gradient that fades out into the surrounding landscape towards the edge.