@Hobbes – We may not be geographically isolated by region (even though we are by neighborhood), but I think we are increasingly Balkanized as far as information goes. The partisan divide is at its greatest in the media, when one side thinks that the media can’t be trusted (except for their one special channel that tells them the Truth), and the other side doesn’t bother with that channel because they know it’s all lies. With the exception of sites like Fluther, I think the people also have their loyal websites that feed them only the news and ‘facts’ they want to hear. (And even here, where one might be exposed to different viewpoints, I don’t think people really mull them over in a considered way, as much as they repeat the same fights over and over. For example, I’ve had some political arguments with the same people, multiple times, and no one has given an inch.)
Decentralized information is a lot like looking up random Internet web pages. You might get good information that you can’t hear anywhere else, but it’s just as likely that you’ll get some nutjob’s conspiracy theories that are no longer vetted by anyone but the nutjob in question.
In other words, I might live next door to a guy with a gun rack and a Confederate flag on his truck, and the couple with the rainbow sticker on their Volvo, but I don’t think they talk to each other or watch the same TV.