I don't know how many people actually follow or pay attention to Google Pagerank updates. I do follow updates, but don't spend a lot of time with them. After an update, I check a few pages to see if I notice any changes that stand out. I don't have time to do a bunch of analyzing or anything like that.
There was a recent Google Pagerank update that you can read about here:
Google Pagerank Update June 27, 2011
It was followed by another Google Pagerank Update on July 18, 2011 most likely to make a few adjustments or tweaks, which is a fairly common practice.
Google was fairly generous with many sites and pages after the June 27th update and the follow-up one on July 18th appears to have corrected some of the generosity. There were a few sites that also lost pagerank that probably shouldn't have. Even google.com was reduced to a pr9 from a pr10. After the July 19th, update they are back to pr10.
I actually figured we would see this update happen because some people reported rank increases that were almost too good to be true. And, a few popular websites actually lost a little bit of pagerank that maybe shouldn't have.
Boonex.com has been a pr6 for a while now. They got bumped up to a pr7 after the June update. Now Boonex is back to a pr6.
There are a number of other sites that had a similar scenario happen to them.
Google likes to keep us on our toes and guessing.