Here. Apparently, 0.03% of the web is made up of blogs, but that's still enough to change Google's basic assumptions:
"They presumed that technicians at USC would link to the best papers from MIT, to the best local sites from a land trust or a river study - rather than a clique, a small group of people writing about each other constantly. They obviously bump the rankings system in a way for which it wasn't prepared."
Because of this, Google is likely to set up a "Blog" tab and take blog results out of the main searches. I'm on the fence as to whether the latter is a good thing, but it's nice to know that something grassroots like blogs can still change the world.