The Patriots are still the favorite. Until Cassel shows me that he can take a great team and single-handedly make them terrible, the Patriots are still a great TEAM.
There is a huge range between great and horrible.
Cassel won't turn the team into a 2-14 team, but you really can't consider the Pats the AFC favorite. Not that I am writing them off as a possibility. 2001 could repeat itself, but they are not the favorites.
I still consider them the AFCE favorite.
Chargers I would say favorite for the AFC.