I don't have regional breakdowns of those numbers. The best I could offer you is the markets that were directly involved. In baseball, for example, the spike in 2004 and the drop in 2008 are both unsurprising, given the former was Boston ending 86 years of futility and the latter involved Tampa Bay (which, combined with the Marlins' shitty attendance, would actually seem to suggest old people don't care about baseball much at all, but I wouldn't be able to argue that stance one way or the other with any sort of conviction).
I'm guessing baseball will actually maintain this popularity, if not see an increase, given the influx of exciting young talent outside the major northeastern markets with guys like Hanley Ramirez, Troy Tulowitzki, David Price, Tim Lincecum and most recently Stephen Strasburg (and Bryce Harper on the way). With the way we seem to be moving on from the PED debacle (or at least starting to), the only thing that I can see killing baseball at this point is Pujols getting busted. He and Griffey are the last two names every fan in the country wanted to see on any list of that sort, and Griffey has been able to leave quietly.
