I have not heard whether Cassel will be back with the team and ready to start.  Obviously it's up to him.  Belichick will keep quiet about it probably either way.

Belichick said this week about Kevin O'Connell:

“Kevin learns every week,” Belichick said. He’s a smart guy. Football is important to him he works hard at it and I think he gets better on a daily basis. He’s getting better through the course of the year in the opportunities that he’s had, which have been limited. But he’s always ready to go when we put him in there."

Sounds to me like if Cassel doesn't feel ok to go then Bill trusts O'Connell to start.  As an O'Connell fanboy this would be very interesting to see.  As a Pats fan hoping to win out, this could be worrying to see.

Also on O'Connell, Ellis Hobbs said:

 “In practice he definitely has a strong arm on him, can throw the deep ball, can throw the intermediate routes. Just like any quarterback we have, they’re great in the system. They can go and just put the ball wherever we need and let our skilled players do the rest.”