If I were Mike Tice, why would I want to risk a potentially good season, let alone his job, and trade away the team's leader and starting QB for the 6th pick in the draft? Sure, they'd most likely be able to get Byron Leftwich with the #6 pick, but also at their own #7 if they really loved the guy. Backup Todd Boumann left for the Saints, and without any established vets around (Griese doesn't count) that would leave Leftwich at the helm in his rookie season. Not the best scenario for the Vikes or Tice.
The only reason I can see that the Vikings would want to trade Culpepper is because they don't think they can resign him next year. If that's the case......anyone interested in trading for Moss? Heh.