The Pats put the franchise tag on Vince Wilfork today.
Article here: New England Patriots assign franchise tag to Vince Wilfork - ESPN Boston
In summary, the tagged him and made the statement that they did so to allow themselves more time to negotiate a contract. Wilfork's camp says the same thing.
I get the feeling they really are doing this to keep him from getting tempted by other offers. I think the Pats will only trade him if they are offered a lot (i.e. 1st round pick or multiple picks). Not something I am willing to give up.