On another blog someone posed the question, suggested by the chance that Pittsburgh and Philadelphia might play each other, as to whether any other teams from the same state had ever contested a Super Bowl. The answer, of course, is yes.
I am sorely tempted to leave at that. But then I couldn't finish this post as intended.
The fact is teams from the same state have played each other twice. In 1991 the Buffalo Bills were defeated by the New York Giants [yes, I know the Giants play their games in New Jersey] and in 1995 the San Diego Chargers were defeated by the San Francisco 49ers.
There are those, however, who would say that New York (the city) and Buffalo are from the same state only because that's how the boundaries are drawn. There are still other who contend that San Diego and San Francisco a too different to be in the same state, even disregarding that Northern California/Southern California thing. Heck, from where I'm sitting neither truly represents California. Besides, I will argue that San Francisco isn't even in Northern California (just look at a map.)
So I guess the answer to the original question depends entirely on the answerer's frame of mind.
footnote: It appears, from the news out of Sacramento, that nobody really represents California. Everyone is in it just for themselves.