Observations:
1. Brett Favre at 37 or however old he is, is better than Pennington or whoever.
2. Favre's effectiveness this season will depend at least in part on how similar or different the Jets' offensive system is from what Favre was accustommed to in Green Bay, and his supporting cast. That said, the Jets spent a lot of money to have a good offensive line, and they have at least decent skill people around Favre. And since Pennington has no arm, their system is probably not too different from the West Coast system that was the base out of which Favre operated at Green Bay. About the only question that remains concerns terminology. If Favre has to learn all new terminology, it will slow him down some, since his old Wonderlic scores suggest that he's not the sharpest tool in the shed. That's not to say he isn't one of the greatest natural talents ever to play the game at QB.
All in all, this probably elevates the Jets to a contender for second place in the division and makes Buffalo's job a lot tougher. But by no means is it impossible, and I don't expect Buffalo to lay down and die because of it.
Go Bills!