I could have SWORN that the planet/city of Coruscant was mentoned somewhere before the PT made its debute. I don't think that it is said in the OT, but maybe in one of the books? I don't know. My best friend and I were talking about this and we both seemed to know a fair amount of it before episode I.

I know that in the ROTJ SE there is a scene where they show the city/planet partying, but even then I recall we seemed to know that, "yup, there is Coruscant."

Maybe the PT really has polluted my mind.