Do what you like, but I preferred it as it was.
I noticed the change yesterday. I like bill...but think there could be some way to incorporate him into the site without changing from the headshot. Until I actually looked closely at the image, I thought your headshot was a macro image of a thumbprint or something. It took me a few months to tilt my head, just right, to figure out it was a face. I got my eyes checked after that! I still like the headshot - but that may also be due to familiarity. After only 1.5 years frequenting your sites - changes still jar the senses.