Long waiting for Google PR update is now at bestow. Predicted last mid July 2007, it is only a month late based on previous Google trends. This comes as no surprise for us amount of minor Algorithm changes we have seen nearly week on, for around the last 2 months. The last thing Google wanted to do was post an update with some of the bugs that we've seen in the last couple weeks in the SERPs.
The update looks to have started on Sunday, August 5th when Google started giving new sites (PR 0) more Authority. In conclusion about the update starting on the 5th has to do with a brand new site having its Google traffic increase around 5x overnight. Next observed sites that had been incorrectly assigned higher PRs notice a significant decreases (this seems mainly to happen to PR2 sites showing as PR5 or PR6), as well as domains that had expired seeing a PR drop, or a complete loss of PR.
Recently, observed the new website mentioned above which was setup in the end of June drop from a PR4 (this was an incorrect value which actually belonged to another site that google had assigned to both domains) to a PR0, then this afternoon jump back up to PR4 which is inline with the total number of links, and strength of links that are linking to the site.
Estimated in that the PR update should be done by Wednesday night or Thursday at the latest. The big thing was haven't seen finish is the main domain PR update, and update of PRs for internal pages.
Resources: Daryl Quenet