FWIW, the Vikings were emphatic that Percy Harvin would not be traded, even as they were shopping him behind closed doors at the combine.
I think if someone offered anything for Flynn, he'd be gone. That said, there is some logic in keeping Flynn for one season. Maybe Wilson actually gets hurt. Even if Flynn doesn't get us a championship, he might play well and raise his value to other teams by several magnitudes, the same way Alex Smith did in 2012.