I have to say that background was very distracting. Also this pic is a little washed out. I like the work here, so I wanted to give it a more objective view. Here is a literal two minute touch up (so pardon any areas not picked up in the background):
Added the darker background, and tweaked the color saturation just a touch. I am not the PS genius some of our denizens are, but now I can look at this with a more objective eye.
So:
I think the flesh could use a very thin wash or two of color to add some tone to it. Also the flesh contrast could be a tiny bit more extreme.
Hotspot highlights on his hair.
Those are really the only things I see, that I would tweak. Its a really good piece with great color choice.