In addition to the Madden cover, Favre has to overcome the mojo of playing somewhere other than Green Bay. It's a tall order.
I also heard that he walked under a ladder on his way to camp, tripping over a stray black cat, and fell smack into a mirror, shattering it. With all of this bad luck, I predict he will spontaneously combust into a fireball of ash by week #3. Sorry Jets fans.