Great answers, all! I really appreciate the suggestions (well, maybe with the exception of the knife...not that we didn't consider it!) Okay, here's what I actually did.
On the way out on day three, the boat was pretty quiet. I think most of us were fuming. The camera guy was fiddling with his equipment, as usual. Strictly on a hunch, I wandered over to him and his group and began asking him about his camera. He was glad to show it off and talk with me about the places he's used it and such. I showed interest and talked about how I was still using film and stills, but hoped to move up to video, but that I still enjoyed getting the shots I did. In short, I opened up dialogue with him. The remarkable thing was that I didn't even have to approach the subject of his rudeness. This was a person who thrived on attention, and shooting the video seemed to be his way of getting it. Once I "validated" his area of expertise, his whole demeanor changed. On the rest of the dives, he was incredibly better. Oh, he still lingered over his scenes, but he stopped hogging and horning in on what everyone else was looking at. Even his partner seemed better at avoiding collisions.
I just wish it hadn't taken day three to realize this tactic, which I'm sure wouldn't work on every similar situation. Therefore, I appreciate all the suggestions about how to handle these types of breaches of diving eqituette. Thanks to everyone for the comments and advice.