Simple math really: Jags bring loads of pressure, TE has been less then stellar under pressure this season. Fitz is less accurate yet senses the pressure better, Hamdan as seen during the preseason actually senses pressure best out of all three. However with Fitz they allready know what he can and cant do on the field and Fitz is the more experienced out of the three on paper. So they opt for Fitz for this week. If Fitz wins he'll keep the starting job based on record (3-1), if Fitz looses it's most likely TE's job again.
Personally at this point I'd love to see Hamdan, then again I know what he can do out on the field and just feel he would bring the wins in. But that would mean playing Jackson over Marshawn and TO, Reed and Steve Johnson over Lee Evans (those players are the best matches for Hamdan his style). Maybe if Fitz looses we'll get to see that, it kinda depends on how Lee his work ethic and attitude is percieved by the coaches. Performance wise he's been the better one on the team thus far so that would be a tough sell to the team and the fans.
I do like the Fitz choice over TE for this one game though, listening to the TO press conference confirms that it was the right thing to do to at least get some spark/fire into the offence going into this weeks game. Choosing the guy with the best win/loss ratio also helps with the message you are trying to send to the team; win.
Fitz as a qb however, I dunno i'm not sold on the guy, flashes of brilliance followed by uber epic fails, yet he shows more then TE has done this entire year aside from game 1.