Beautifully done! The only thing that is bothering me a little, is that some of the trees (which I suspect are the 2D planes) appear a little flat. Have you got them running just the diffuse and ambience or did you click their alphas into the values as well? (Mostly, I mean those largish trees left/middle, but there are a few others.) They need more contrast, and I think playing with the alpha channels would give you that.

Could be worse, could be raining.