Dave Winer thinks that because he's not ranked where he wants to be, “Google's algorithm is quirky, or the implementation is buggy, or both.” I've also noticed that I'm no longer the first non-Apple search result for Janie Porche, and I've even fallen to third-place on naked desktop people (although amusingly enough, the top two are Ugo Cei linking to me).
Google must be in a tough situation. When they started out, PageRank was a really neat idea, and worked very well. What it wouldn't have counted on was the huge increase in small, insular communities who do nothing but link to each other every day. Look at the Java-blogs community, for example. Half the entries I read are links to other blogs I'm subscribed to. (Which is a good thing, each post accretes a little more information, a pearl solidifying around an irritant in the blogosphere)
While there are a lot of weblogs, we're still a tiny percentage of the population of the web, and even ‘popular’ weblogs still only have a few thousand visitors a day. Thus, Google are probably doing quite a lot of work behind the scenes to reduce the inordinate influence blogs have on their page rankings.
And more power to them.