Wow, this image is awesome, and a great sign of things to come...
As a suggestion, I would put a displacement map on the leaves. This will add extra realism to the image because the curved leaves can pick up specular hits from the light, and also they will not look like flat pieces of geometry when perpendicular to camera. For a simple displacement example, just try a radial map, but I am sure you will have a good idea for a more realistic displacement map.
Tests I have been doing in this area recently have come out extremely well. Not anything to show yet, but it really does help.
Congrats on the lovely image!