I think they're adjusting for over-inflation of high PR range , trimming the algo (might be increase threashold) means reducing score of all across the PR spectrum ?
Bigweblinks dropped from a PR7 to a PR4 as well, all these sites have spent a packet on links since April.. Oh well the writings been on the wall for a long time, people just wouldn't believe it.
More important than dropped PR, their indexed pages are also dropped tremendously. I guess we already know why this update was so late. I think google engineers made lots of trial and error to fix the issues after this big and risky update. This shows me that they selected the way to rescue reputation of pagerank instead of killing it. So my PR6 and PR4 directories will get lots of reputation now? Please dont ask urls if you dont want to be a sitewide sponsor and ready to pay good amounts
I think you have to ask yourself 'where's the value?' If your site really adds value, I think you are immune from pr and algo updates. Quality wins online : )
I bought a listing from AliveDirectory. Spent about 1500$ buying links just 5 months ago. Hmm guess paid directory business is over.