As this thing dragged on, if it had gone longer, the Patriots' leverage would have diminished more and more and more.
As I posted here ad naseum, the second that we franchised Cassel, the chance of keeping him was non-existent. At the end of the day, we would have traded him for a bag of balls if it came to it. We just didn't have money to do anything in free agency, and every one knew it. The timing here -- getting it done quickly -- was almost important. The only reason Denver got interested was because another deal was imminent. Teams would have loved to see this drag on, watching the Patriots suffer while players like Gaffney got away with the patriots have zero dollars to do anything in the crucial early stages of free agency. This had to happen, and it had to happen quickly, and keeping the player was simply not an option.
It was like found money all along. You have no reason ever to expect to get something from your backup quarterback when he turns free agent. The franchise tag and last year's unfortunate events gave us a shot to get something for nothing. As it turned out, we got plenty of something -- a great second round pick (the second best) and an opportunity to take another $4 million of the books. I think we can debate the second part of the equation -- was the front office right to really think that Vrabel was not worth $4 million on the cap. But it's an entirely different question. They thought it was worth something, and they got it.
Would I have liked a swap of 3d round picks, or something else? Yes. But I've predicted all along that a second round pick was the most we were ever going to get, and so I'm hardly disappointed now to find that it is an excellent second round pick, and we also got something else in terms of a team to take Vrabel (and not one in our division which I think was important). Plus, we didn't have to go through the hard process of cutting one of our best all time Patriots. I'm sad about Vrabel moving on, and I am skeptical whether the money freed up was more important than the player, but as I said that's a separate question.