I want to add, I doubt Romo approves a trade to just any team.
As others have quipped, perhaps the team owes him nothing, but Jones loves him and won't just trade him to any team to rot for his last couple years (Browns, Niners). Jones has always wore his heart on his sleeve.
I think NYJ, DEN, AZ (Palmer is declining fast) and BUF as a dark horse (despite Taylor) are the biggest chances for landing him in a trade. Someone brought up Houston, and that would be interesting, too. Brock is horrid, but they do have a lot locked up in him, but they are missing a dynamic QB (simlair to AZ's situation).
Edit, I see you covered the Brock deal in a further post, Stash

(as I was replying)