There's no way they voluntarily suspend a football season. There is just way too much money involved. They have to play to get their cut of the conference TV and bowl revenue, and they have to have that to play for the rest of the athletic department.
Be it the right or wrong thing for them to do, that is the reality in this day and time.
I think they would have to weigh the loss of a season or two of football revenues vs. a long term drop in donations and research funding. It was reported this weekend that the 3 most powerful men at the university had been covering up Sandusky's actions since 1998. And again, this news cycle is only in its infancy. More damning details are sure to follow, and they'll probably still be coming out after the season is underway. And if they choose to play this season, those details will be getting 3+ hours of exclusive coverage on ESPN every Saturday. That can't be good for their endowment.