From what I see this
PR update is about relevance. Statcounter.com has dropped from a 9 to a 6 (having dropped from a mighty 10 at the update earlier this year). Those guys have over a million inbounds links according to G. Heaven only knows how many Yahoo! reports for them - I don't need to look to see it will be a big number. Of course, the sites linking to them are those using their code - a tiny percentage will be sites relevant to web stats as a topic.
Also noticed apple.com dropped to a 9. Shame that.
NB I'm not saying that I think inbounds are the only factor affecting
PR. Just that the relevance of inbounds has been subjected to much stricter criteria this time around. Which is a good thing surely?