A real Vikings fan wouldn't want Favre on their team, no matter what Packers fans think. I know many Packers fans that don't even want him on Green Bay this year, and some of them are even hoping he gets traded to Minnesota. Obviously everyone has a different opinion on how Favre will do this year, and I'm someone that thinks he's overrated at this point in his career. But when talking about Favre and the Vikings you have to understand that most true fans don't want their bitter rival playing on their team, even if some think it will win them a Super Bowl.
Also people need to realize Favre is an absolutely terrible fit for Minnesota. With the team they have they need a QB that will manage the game, not make mistakes, and just make a play every now and then to keep the defense honest. They don't need some rival legend trying to prove he still has game while trying to be the hero. Minnesota has arguably the best defense and the best OL, and a top 5 RB. They can win the Super Bowl with a QB that won't lose them the game. Favre is a QB that could lose you the game. He plays a risky style of game which has led him to a lot of game winning TD's and a lot of game costing INT's. He doesn't fit into Minnesota and people need to realize that.