Jeremy Zawodny's blog: PageRank is Dead: "Google has a really hard problem to solve. It's not unlike the Heisenberg Uncertainty Principle. PageRank stopped working really well when people began to understand how PageRank worked. The act of Google trying to 'understand' the web caused the web itself to change. Blogs are only a recent example of that. Oddly, unlike many of the previous problems with Google (see also: search engine optimization companies; link spammers; google bombing), blogs were not designed to outsmart Google. They just happen to use the web and hyperlinks the way we should have been using them all along. Now they're being penalized for that, it seems.
It'll be interesting to see how Inktomi and Microsoft handle this 'problem' too.
Oh, I should note that this could all be a bug and I'm just using it as an excuse to ramble. But you all knew that, right? My readers are smart. All three of them. :-)"