Hmmmm.... Very Woody Allen-esque. I'd like to see a bit more DoF and less reflection on the glasses. You need to consider where you place your lights as well; the catchlights are in the dead centre of his pupils, which gives him sort of an odd, appaerance if you look closely. All of those are relativley minor points; the lighting is good, focus on the eyes is sharp, so you've got the main points covered.
Thanks tirediron. I'm looking to get one of those cords for my flash so I can move it around since I'm always taking these headshots on a spur of the moment basis. I'm not entirely sure I understand you depth of field statement. Would you mind elaborating a bit?
I'd probably have stepped up the aperture a little to allow the front of the cap to be in focus (increased DOF). The reflected flash in the glasses would have been a problem for me also.
I like the shot though, not sure why he has a seemingly sad expression though?