Unless we are getting a bonafide player in return, I dont think it is worth it. Our o-line has been having trouble opening holes in the run game and stew almost never goes down on first contact. He might be invaluable to us now with KB out.
I have no idea where we got all this "Rivera has a steel boner for vets". Ummmmm... does anyone remember the Fox years? FOX certainly exhibited this trait, to the Nth degree (See Tyler Brayton starting over CJ, Foster starting over Williams). Ron has certainly given rookies opportunities to come in and start with the big boys.
Stew isn't going anywhere. We've been babysitting his fat contract and injuries for years now. If he wants to get re-signed and get starter quality money (probably not here though) he is going to have to show up and put together a big season.