Scout is usually a very reliable source. So, I guess it is official.
http://vikings.scout.com/2/508835.html
Scout.com has learned that the Vikings’ trade of Daunte Culpepper to the Miami Dolphins has been approved.
The Vikings traded Culpepper to the Dolphins for a second-round pick earlier Tuesday, pending Culpepper passing a physical. Culpepper’s physical with the Dolphins satisfied Miami officials enough to finalize the trade.
The Vikings will receive Miami’s second-round pick in the 2006 draft.
http://vikings.scout.com/2/508835.html