Now that you mention it, weblogs do a pretty good job of breaking culture up into simple, digestible bits of info-edutainment, just like television does. The rise of the sideblog (or daily links, or micromemes, etc, whatever they're called) is a testament to the fact that we're doing a more and more efficient job of finding and metabolizing all of these news stories and curiosities -- each mostly out of context, as we lump Jako and Paris Hilton links with articles about Iraq or trampled shoppers. It's not that different from network news in the way that it trivializes.
What we (as modern weblog-type geeks) understand is that when curiosities and ideas are discussed within a community - even the relatively small readership of one website - the bits are given value, and placed it within a context of shared experience, idea exchange, and morals. I think that weblogs (and the web at large) stand apart not because the process of writing and responding is interactive, but because the interacting and discussing builds relationships, a moral context, idea connections... and other sorts of personal developments that rebeccablood once outlined two-thirds of the way down her original essay on weblogs (
http://www.rebeccablood.net/essays/weblog_history.html ).
Beyond that, I don't think it fundamentally matters whether you get your digestible bits from TV or films or magazines or brief chats with strangers. I don't think there's much value in facts (or in keeping up with current events) unless you really take the time to discuss them with family, friends and community.
It comes down to stories, I think. Water-cooler chit-chat and quick comment thoughts are no substitute for real stories, told about our own people, that help us better understand how to live our lives. Once upon a time, in the days of tribes (or churches, or town newspapers) people must have naturally learned only about events and ideas that had been community filtered - stories that meant something within community context. This preserved identity.
I guess modern media is, for the most part, filtered only to sell. As such, most of it is rendered worthless. Weblog social networks filter better than network affiliates, but it's still not really a substitute for dinner table conversation.
Imagine if you limited media consumption to 5 web pages per day, or 30 minutes of television, and spent the rest of your media time discussing those few pages with people you cared about. Wouldn't that be more productive than just reading and watching as much info and entertainment as possible? There just isn't time anymore.
Sorry for rambling. Now, back to NPR.