The sheer volume of posts here about Pitt, and the fact that a number of posters admit to going over to the Lair regularly to monitor board traffic there, suggests something different to me.
I just don't see PSU developing an in conference rivalry like UCLA-USC, Alabama-Auburn, Michigan-Ohio State, or even Cal-Stanford, as things presently stand. A three way rivalry with Michigan and Ohio State? Maybe, but that seems awkward. Michigan State? No. Maybe Rutgers at some future date if they improve their program a whole lot, but I'm not betting on that.
It is telling that PSU has played Pitt something like 98 times. Is that merely a consequence of the fact that both schools are located in the same state? Not sure I'm buying that.
The only thing preventing it from being a rivalry in the truest sense is that the teams do not play in the same conference, and Pitt simply does not have and will not have a football program with the national stature of Penn State.
I could see the development of an in-conference rivalry with Maryland if they continue to improve. Border states, the schools are about 4 hours apart and we compete for the same athletes -especially in the DMV. Lots of Pennsylvania kids go to Maryland and vice versa.