Lots of this has been said, but I will add my voice in concurrence:
1. Trying to obtain advantages including by stealing signs is not the issue. Everybody tries to steal signs because only an idiot does not want intelligence before an engagement. The issue here is seeking and gaining advantage by KNOWINGLY and WILLFULLY violating a published and objective rule over a period of YEARS.
2. Michigan is showing its colors as dirty. The instinct to sling mud and cover up is shameful. Is this what they want to teach their students to do when caught in misbehavior?
3. Who cares who ratted them out and what relationships existed among those who caught Michigan cheating. The issue is the cheating.
4. If no punishment is meted out for this cheating, why not set up electronic snooping for the helmet communications in the future? Why not bribe opposing coaches to reveal game information? Why have rules at all? The point of consequences is not always merely the bulwark against the specific infraction at hand, but rather to reinforce the notion that rules exist and we should play fair.
5. This is a big deal. Statistics show Michigan fares far better in key metrics when cheating. People's livelihoods are made and broken based on how college football games turn out. Draft positions go up and down; coaches are fired or given raises; etc. Literally millions of dollars change hands in ways directly influenced by these scores and statistics. For anyone who knowingly lied about the behavior and profited as a result, we are now potentially talking about actual fraud.
6. The choice between immediate and delayed consequences, between up-front response and "letting things play out" is a false dichotomy. It is both possible and appropriate to apply an initial consequence with the intent to select a final punishment once the scope of the misbehavior is better understood. Those pushing to wait are really pushing to avoid consequences now (when the cheating is truly bearing fruit) and hope never to face them at all with the passage of enough time.
7. NCAA ,B1G, and all persons (natural and otherwise) harmed by this cheating need to hold Michigan's and the coaching staff's feet to the fire to come clean and cooperate fully. All punishments need to be on the table. If a years-long interstate cheating ring isn't worth investigating, the next cheater in line will take this to levels we probably can't even imagine.