This move makes no sense and would make nobody happy. While Iowa fans would be ambivalent upon his departure, we'd start getting awfully nostalgic when Ferentz is winning his old familiar 9 games in Ann Arbor and Mark Farley's* putting the finishing touches on a 4-8 campaign. Meanwhile, Big Blue's been assuming for the past, oh, 12 months that the job will be going to a Michigan alumnus whose team just so happens to have been #1 for the longest amount of time this season.
Either way, there are way, way too many rumors circulating (nothing's been independently verified, so specifics are a no-go) for there to be nothing to the story. I still expect Captain Kirk to be on Iowa's sideline next year. Michigan must be very, very tempting to Ferentz, but nothing about his track record indicates that he would leave Iowa for another school in the conference--not even Michigan.
*You know Farley's getting hired if Ferentz leaves.