Although this is not a serious post, I'm compelled to give you a straightforward, serious answer. I don't think that wearing a certain jersey number has any effect on a player's performance. Consider that Daunte Culpepper reverted to his college number (8) after signing with the Dolphins. I'm willing to bet that it was his injury and not the jersey number that perpetuated the problem with his knee injury.
It's no different with any other player who wears a number of his predecessor. I don't think that the person who eventually wears Ricky Williams' number or Fred Evans' number is going to have problems in their careers. The bottom line is that it's just a number. John Beck is nothing short of a spectacular college quarterback and he should prosper with this team in the future. The early reports we're hearing from camp should give you goosebumps.
I agree with a couple of the posters here in regards to Fiedler. He did a fine job as a Dolphin (remember the SNF comeback game vs WAS or the endzone scramble vs OAK?). Jay played hard for this team and I give him all the credit he deserves. Heck, the last time we were in the playoffs was when he was the quarterback of this team. Ray Lucas? Nope. Brian Griese? Fuhgetaboudid. Gus Frerotte? Close, but no. Joey Harrington? Don't remind me. A.J. Feeley? I just threw up in my mouth.