$20MM, less what they can recover from the assets of Paterno, Sandusky, the other two guys, and any potential insurance settlement. There is a very good chance that Penn State ends up net out of pocket of less than $10MM for allowing a pedophile to run rampant on their campus over over a decade.
The victims of the Catholic Church abuse have ended up with about $1MM per victim, depending on the assets of the diocese in question. If a victim was unlucky enough to get molested at a small diocese that did not have significant assets, then the settlements were less than $100k per victim. If a victim got molested at a wealthier diocese, such as San Diego, the payouts were closer to $1.1MM per victim.
The Catholic church scandal is a direct comparable to what the Sandusky plaintiffs can expect. It is a very similar situation in which a larger organization protected the criminal behavior of an individual over an extended period of time. Luckily for the Sandusky victims, it will be pretty easy to implicate Penn State in the abuse, which means access to much deeper pockets. Unluckily for them, the Catholic church settlements set a guideline for payouts. With fewer victims and a deeper pocketed defendant, the Sandusky victims could have hoped for a bigger payday if they had gone first.
It is very unlikely the Penn State victims will see much more than $1.1MM per victim. While there are technically 20 victims, I expect a few to be thrown out because they will be unable to prove they were actually molested. Assume 2 or 3 are tossed out, multiply by $1.1, and round up to $20 million to provide margin of error.
Penn State has grossed several times that number in the last 15 years since it became abundantly clear that Sandusky was a serial child rapist. It really is up to the NCAA to punish Penn State, because otherwise, from a business perspective, Penn State clearly made the right decision in burying the Sandusky situation as long as it did.