Hello.
Basically, Nick Saban has been given a 'tabula rasa' in molding the Dolphins team for 2005 and onwards. He does not have to be held accountable for the previous regime's decisions, such as trading a 2nd rounder for a 3rd string QB. He should be making decisions that are the best for the team right now, in consultation with other coaches, scouts, capologists, etc.
So, if A.J. Feeley isn't living up to his expectations as a 1st or 2nd string QB, he will more than likely be cut altogether. His salary and heightened expectations really cannot relegate him to a 3rd string QB status.
That said, my gut feeling as a fan is that A.J. Feeley will remain on the team as either a 1st or 2nd string QB. He still has the talent and can still contribute to the team as a whole, recent bad on-field decisions notwithstanding. In fact, he got slightly better as the season progressed to an end last year, with the Dolphins winning some games.
However, the real tension lies in the 3rd string QB spot! Sage may well have to fend off Brock for the final QB roster spot. I'll admit to being surprised by Brock's QB'ing in the pre-season so far and can only truly hope that if he does not land a roster spot with the Dolphins, his 'audition' will land him a spot with other 31 NFL teams.
Enjoy.