Here are the conditions in which I would welcome Peterson in the Cowboy fold...
1. The Vikings release him... No trade... no giving the Vikings any draft picks. No giving the Vikings any players.
2. He passes through waivers unclaimed. I think the odds of this happening being pretty good. I don't think anyone would claim him and assume his 2015 contract parameters.
The Cowboys could then negotiate with him for a contract that was much lower than what he was going to get from the Vikings.
Those are my conditions.