The biggest decision I've ever had to make. This month.

Over the last few years, I occasionally see a photo of myself and more specifically my scalp and, more and more, I dislike what I see. My hair has been thinning since college but the last few years my hair has seen a recession not unlike that of our nation's economy. I have light hair and in direct sunlight it looks pretty bad.
Every time I see one of those pictures I contemplate shaving my head. In fact, a number of times I've said "one more hair cut then I opt for the Bruce Willis look." I always end up chickening out, cutting it very short, and then resenting myself when it starts to grow in on the sides more than the top.
The longer my hair gets on the sides/back, the more noticeable the thinning/receding top is. If I keep it short, it doesn't call attention to itself but it's still there and it's still noticeable. More importantly, I don't like it. Only two things have kept me from going full-shave:
1. Professionalism. People's opinions and how they perceive a shaved head tend to be mixed. I am a consultant and a sales person, and I frequently have to act as an authority in my field in front of large groups of people. If less people take me seriously because they believe a shaved head is unprofessional, that's a problem.
2. I simply have no idea how it will look. Bruce Willis and Vin Diesel pull it off, but it didn't really work for the kid from Powder.
I'd like to get your thoughts. Here is the picture that I saw that prompted me to write this:

Zoomed in at a higher resolution, it's worse. I'm fucking bald.