Ok... I'm a Packer fan. That said, don't count the Vikings out of the race without Favre. Before Favre the Vikings were a 10 win team, with Tavares. All reports say Tavares has gotten better (which, I always take "reports" with a grain of salt).
The Vikings D is still beast mode, but Griffin being out the first game (most likely) is going to be an issue a good portion of the year.
I truthfully--no homer--think the Packers are the team to beat in the NFC North this year (with or without Favre), but they have their own problems. (Secondary & possibly the run game).