We fade to grey
I don't know if it's a preference of yours, but to me you always shy away from having a wide variety of values(?) in your work, which leaves features weaker and a struggle to look around your pic.
I've fixed your pic up on PS on what I think it should be like: http://img109.imageshack.us/img109/3071/idiotm.jpg
Easy job, just pushed the levels inward, and tweaked the colours where the contrasting butchered them.
This has made the eyes piercing, emphasised colder shadows on the face and flaunts your brush strokes.