ND is not going anywhere, even if god forbid Big East football folds up shop. It's not about TV money or BCS berths. ND is unique which is why it is loved and hated by so many. The Big East is a good fit because football membership is not required.
The stability problem has nothing to do with non-football members. It's about a perception problem combined with a ridiculous BCS system. WV is the only ranked Big East school at #25. They just got blasted by the gaggle from Syracuse. Syracuse and Pitt are perceived to be "traditional football schools", why? If the BCS system ends, stability problems go too.
Playoffs are the best answer to a system that tries to keep the championship and the money within a select group of "football schools." Not enough people are complaining and I really don't get it. What are the chances an undefeated Boise State team gets to play in the BCS championship? Zero. That despite pounding Georgia, it won't matter.
It will be interesting to see what emerges with a rebuilt Big East football conference. It's too bad TCU didn't stick around, I think they made a mistake.