Losing Calico has allowed teams to double-team Mason and leave Bennett to be the possession receiver that he is. When Calico returns that will completely open the offense back up. I don't believe that the Titans have been hiding McNair injuries for one second. He did however, get injured in the 2nd half of the Jacksonville game, and I suspect he'll miss this weeks game, but I bet he'll be back for MNF versus GB.
But that being said, if you spent a high draft pick on McNair I don't think you'll see him outperforming guys like Brooks and Bulger by enough of a margin to merit the high draft pick. But I feel all of your pain as I drafted Vick pretty high!