In January, Google VP Udi Manber wrote a tantalizing article [googleblog.blogspot.com] where he said "we made significant changes to the pagerank algorithm in january."
So we've had half a year since that change. What kinds of things do you think happened? Or even more, in what ways is PageRank no longer the original formula, even if the change was earlier than last January? Here are some ideas I've been kicking around:
Internal links and external links on the same page may not be splitting the PageRank vote equally.
PR may be weighted differently according to where links appear in the page template - menu, footer, header, main content.
Multiple links to the same url from the same page may not each get the same piece of the PR vote. Does only one "count"? Or maybe the extra links are just ddevalued a bit?
Run-of-site external links may have their PR vote damped down. I'm thinking particularly about blogrolls here, but other situations might be similar, don't you think?
Links between domains that Google sees as "related" may have their PR significantly damped down. And what about interlinking between a domain and its subdomains? Surely that doesn't deserve an equal slice of the PR Pie.