I think one thing to note is that insiders said that if O'Connel was a year along and not a rookie, he would have been the backup over Cassel. The argument that brady is in trouble because he isn't a mobile qb and had a knee injury is foolishness. You are arguing against yourself....TB is one of the best qb's ever in his ability to feel pressure and slide around in the pocket creating that extra time for the receivers to make a play. People are getting too enamored with Cassel and his ability to use his legs. Cassel has used his legs to help himself out becuase he doesn't have the ability of TB to read defenses and buy time until the play is there.
The drafting of O'Connell has nothing to do with thinking about TB being on the down swing. It is simply the pats addressing a need: Cassel is the backup and will probaly be gone after this year even if TB doesn't get hurt so they are putting a high quality kid in the chain to be a backup in case anything ever happens. BB has always said that the pats will draft the best player that is available in their minds despite needs. They must think highly of OC to draft him that high, but I simply see it as they felt he was the best player available at the time.
Again Cassel has done a great job thus far, and should continue to do so....but I don't see any scenerio, other than TB retiring, that has Cassel the pats qb next year.
EDIT: As far as next year goes, things seem to be lining up for the Eagles to take a run at Cassel. Given Reid's love of throwing the ball, and former pats players, it would be a good fit. I would love to see this, and hope Cassel does great.....just as long as it's out of the division.