He reminds me of a guy who already played for the Dolphins, Ron Jaworski. I've thought that for a couple of years, dating to early in Henne's junior year at Michigan.
Jaworski was a tough guy. You didn't worry about him crumbling. Early in his career the Eagles' offensive line was horrid, 50 or 60 sacks, which ruined the passing game in general yet Jaworski bounced right up every time.
You could see the big arm but somewhat tunnel vision and a long delivery. That made Jaworski vulnerable to seemingly stupid INTs, normally on mid range throws. Jaworski never had high completion percentage but could bust the big play. Again, I see plenty of the same in Henne. When Jaworski threw the 3 stupid INTs to Rod Martin in the Super Bowl, it was the type of thing where they could replay the game and Jaworski could be awesome, the MVP. It was never a guarantee which way he would tilt.
It doesn't hurt the comparison that they wear the same number, #7. In fact, when I saw that picture of Henne from the Buccs game, the one with right arm held high and that at least one poster here is using for an avatar, my immediate thought was, "My god that looks like Ron Jaworski."