Not sure things have to be all that perfect for him to jump. He was ready to take the Vikings job last year. Being a college coach presents different challenges. The pressure to win is the same, but adding in gladhanding donors, fundraising, and kissing 18 year old kids and their families asses year round is not for everyone. For all his faults, Jim is a very good coach, and going back to the NFL may present the chance to just coach again. He certainly would be leaving Michigan in a much better place than he found it, so I think he could leave with a clear conscience.