What do you all think?
That’s brilliant! :yes:
The only problem I have is the trees, they don’t seem to fit. It looks as if you are goind for a cartoon-ish feel, yet the tress try to be realistic. :no:
Other than that, all’s good! 
EDIT - Maybe realistic isn’t the right word, but the tress feel seperate from the rest of the image.
looks nice, but grass could be more realistic and i think water looks like blue snow. Maybe you should try water simulation or add some waves by displacement modifier or something.
I know the trees seem a bit off. I cant seem to get them right. I though shadows might help. Anyway, here’s the real cover that I tried to recreate:
I just used a clouds texture bump map.
There is a certain disquieting sense of flatness to the area around the sign … which may be a little bit too small, as well. (Notice how the original artist made heavy use of abstract textures in this area, including a “blue to black” vertical gradient.) The shape and treatment of the switch-throw could also use more focused attention. Compositing will help.
However, that being said … this is very fine work, even so-far.