Michigan has just as much to offer as Nebraska as far as tradition, support, etc goes. They have a bigger name coach, which doesn't mean better, but it's a recruiting draw. They're also one of the best public universities in the country and Ann Arbor probably has bigger draw than Lincoln.
It isn't a huge stretch to think that Michigan will reassert themselves quickly under Harbaugh. Hoke was a bad coach, not a bad recruiter. Nebraska has a culture hurdle to cross before it can move forward (thanks, Bo) and this team has not been left in great shape. How many of you are solid about what we have at quarterback right now? That's not to mention potential serious problem spots at LB and DE that the new staff is inheriting.
Sorry, didn't mean to be such a downer there. The sky isn't falling here by a long shot, but Michigan is a formidable opponent in any recruiting battle.