Here's how I see it.
Brett Favre maxed the system to the ultimate. He's still playing a game he loves at the age of 39. He's still getting paid 12 big ones a year. He's still going into the HOF. More power to him.
The Jets, for whatever reason, have been a star-crossed franchise since Joe Namath enabled them to usher in the modern era of the NFL in SB III. Their fans have been starved for a winner for decades and, today, are furious beyond human comprehension at what the Giants accomplished last year (I live in NYC...believe me, they are beside themselves). Now, they have made a desperation move with a very low probability of success. In the history of the NFL, only one 39 YO QB has ever put up a great season (Phil Simms).
My prediction? Favre will have a couple of big moments that will win him the praise of the adoring masses in New York, but by sometime in November the fans will be booing him, the brain-dead sportwriters of the Daily News and Post will be skewering him and Tannenbaum and the ownership; the Jets will be lucky to end up 9--7. But, guess what, Brett will want to come back for his final twelve mill in 2009 and there will be nothing that Mangenius will be able to do about it. The only good news for them will be that they only have to give up a Fourth Round pick...