We don't hear diddly about much else other than Seattle, and now Hong Kong (Runner's Havens et al).
But I agree with Chaemera, no one is forcing you to run in Seattle, etc. To make things easier, my last SR game was set in my hometown of Toledo, Ohio. I figured that the players would find it easier to aclimate to the game if they had some familiarity with their surroundings. It was a blast turning the Glass City into another sprawl complete with a corporate presence, unique gangs, sports teams, local government, military presence (yes there is a local military presence here), and other characters of interest. Not to mention mapping out itsown unique Sixth World "history". I still get giggles that I turned the most affluent and in my opinion "snobby" neighborhood in town into a blasted-out, free-fire zone.
Now that I'm getting into SR4, Im taking my old notes and updating for future use.