Being an intrastate team, both the Steelers and Eagles do have some type of rivalry, it's only natural. However, being in different conferences seems to tone it down some, at least I think so.
You won't find many people that like both teams that's for sure, but if you talk to either teams fans, the other isn't generally near the top of the list in the rivalry category. Although, Eagles fans hate everybody so I guess maybe there's some merit to it.
The Eagles usually have their hatred aimed at teams like the Cowboys and Redskins, while our Steelers are mortal enemies with the Ravens, Browns, Bengals, and Patriots.
At least Ben seems to think there's a serious hatred for Philly: "We definitely want to get back on track. But it's probably just as much Pittsburgh versus Philadelphia," Roethlisberger said, via The Beaver County Times. "It's not a division game. It's AFC versus NFC. But no matter what sport it is, it seems to be Pittsburgh versus Philly and a general hatred. That's what I've noticed since I moved here about Philadelphia."