One of the key problems of course is the floating doodads. They detract from the natural image and cause the viewer to realize "oh its just warcraft" lol.
THis can be fixed with a simple high adjustment. Use Ctrl+Page up and
Ctrl+Page down to fix this. Or place shrubbery or other natural objects in the way to cover that part.
Also, try varying sizes to the doodads, such as the rocks. It gives it a more natural feeling and keeps the viewer from looking at too much of the same thing.
Height variation of the ground surrounding the lake would also help the picture
Overall, good work on it though. A few touchups and it will be great