As I've stated before this guy is just going to continue to have a nice NFL career.
Meaning, as others have stated, he is good enough to stick around, good enough to be a quality back-up and is a good locker room guy.
This is not meant to be as insulting as it sounds but he will leave no real mark on this league. However, he is probably going to play no less than 15 season (maybe more, like Kitna), and after scoring some pretty good dollars from Buffalo on his first and second contracts with the Bills he is a 2-3 million dollars a year back up (starting last year) and will likely continue to be so through the remainder of his days.
Jumpin' Jiminy, that is a successful career when you can walk away after 15 or so years with a pension and having made between 30-40 million dollars.
Good for you, Fitzy. Good for you.