I think you're close, but I would give a bit more credit to the Bears and Packers:
Vikings 12-4
Packers 12-4
Bears 9-7
Lions 7-9
There should be a pretty good race between the Vikings and Packers for the division title. It's kind of interesting that these teams have the same strengths and weaknesses. The Vikings had major O-Line problems, but their line has played together a whole year now, so they might gel. The Packers also had O-Line problems. Both teams have amazing passing attacks (though the Vikes might suffer without Sidney Rice) and both have first rate run defenses - the Packers were #1 and the Vikings were #2 last year.
The Bears are a borderline playoff team. They have a great defense, but I am completely unimpressed with their offense. They could win a weaker division, but they'll have their hands full with 4 games against Minnesota and Green Bay.
The Lions are clearly on the rise, but they have a lot of young players who need a bit more experience. Look for them to contend in 2011 (if there is a 2011).