Like the public radio stations, maybe we're fooling ourselves if we think we're not writing for Google, as they are fooling themselves into thinking they're not creating for NPR. -- Dave Winer
I think the central point of Dave's thesis is sound. Many blogs are editorials; opinions on news items or other commentary found elsewhere on the web. We write our thoughts on the story and link back to the source material driving traffic to those sites. This increases their page rank.
PageRank relies on the uniquely democratic nature of the web by using its vast link structure as an indicator of an individual page's value. In essence, Google interprets a link from page A to page B as a vote, by page A, for page B. -- Google Page Rank
As more blogs link to a story the more votes it receives and the more traffic driven to the site. It is this page ranking system that makes Google Search so useful. I can be very certain that the first 10 items in the search results are relevant to what I seek. This increase Google's value to me making me come back to Google each time. This ensures Google a market for it's advertising.
So, the question is, are bloggers really independent or just the "sucker fish" on the underbelly of the whale?