Outside of his 6 TD outburst against Arizona, Favre played pretty poorly on the whole last year. And this is including a number of scenarios where where he really got bailed out - one that stands out for me was the first or second game, when he literally just tossed up a duck on 4th down that Stuckey somehow came down with for a score. Worked out well, but was not exactly a high percentage play. As a Jets fan, it was actually pretty painful to watch.
In 2007, Pennington got a bad rap and Clemens was, well, pretty piss poor. At the same time, don't forget that we brought in Faneca and Woody and Jenkins prior to 2008 - really changed what the team was capable of and into more of a power running game. Sadly, I think Chad was a MUCH better fit for that kind of offense - he was just put in a position in 2007 where he had to play to his weaknesses. Chad was a great game manager but couldn't exactly create throws on his own in a comeback scenario where CBs could just sit back on the routes.
Likewise, Favre is actually a terrible fit for Minny's strengths right now. They are a power running team first and foremost - and a dynamic one at that - and play good defense. If I have a team like that, the last thing I want is a QB throwing 20+ INTs.... I want an efficient QB who is smart with the ball and that defenses have to respect just enough to open things up and not stack the box constantly.
I also think Tarvaris gets a terrible rap as well. He actually looked pretty solid those last few games he started in the regular season. (We'll leave the playoff game out, because he was not great there). Still, he was better statistically than Favre for the majority of the season. I also honestly think Sage is a better option too right now.
I love the storyline, playing the Packers 2x a year, etc etc... but especially with the injury, Favre's best years are clearly behind him. I suspect people who think he'll be the savior for the Minny passing offense will be very disappointed.