You'll probably disagree with me, but I firmly believe that, because of Apple, AT&T, VZW, and soon, Sprint, have been upgrading their network to support the iPhone. -- CheckSite.us | YourIP.us | Reverseip.us
Carriers are always going to upgrade the areas that give them the biggest return on their investment first, ie Cites and other heavily populated areas and really they wouldn't be a very good business if they didn't.
As long as corporations run our wireless and wireline infrastructure, if you choose to live in very rural areas where you can't even see a neighbor, your going to be the last the get upgrades. Like everything else it's a trade-off of where you choose to live, congestion and everything right at your fingertips when you live in a populated area like I do, NJ or open spaces and driving half an hour to the supermarket (not saying you do, but my parents lived in a place like you describe and it was a half hour drive to the supermarket)