First some full disclosure. I am not a Vikings fan, and definitely not a Favre fan. However, I love AP and Harvin, but then who doesn't :-).
I wanted to post this link a while back, but it was always after a loss and did not want this taken the wrong way. This seems like a better time.
Most the the article is not relevant, but this is the part that interested me:
After the game, Manning made a point of stressing that his familiarity with White was a product of countless repetitions during offseason workouts, a reality of modern football he hopes won’t be curtailed in the next collective bargaining agreement between owners and players. Whereas a vast majority of his peers would undoubtedly relish some additional downtime in March, April, May and June, Manning is staunchly opposed to the NFL Players Association’s push to place stricter limits on OTAs.
This is what the Vikings miss with Favre. Yes, he is a veteran and does not need camp, but he forgets that camp is not for him. It is for the rest of the team to get reps with him. Missing camp makes it especially difficult for the "non-stars" and the younger players to connect.
However, all is not lost. Look at this team: Favre, Moss, AP, Harvin, and that is just on O. Any two of those players makes any offense in the league a contender. All four makes MN the football version of the Miami heat, or at least the Celtics from their championship year.
Favre missing camp + early injuries delayed connections a bit, but with more time together the team should gel. If they can get the chemistry just right this team can beat anyone.