Yeah first update in a while. To be honest it does not really mean much at all these days. I noticed sites which are clients who dropped from PR6 > PR 5 have increased in Traffic, yet clients who increased PR from PR4 > PR 5 have actually had a slight drop in traffic.
I prefer to use other metrics like Ahrefs domain ranks, Domain Authority, Page authority ect ect...
I notice expired domains took a huge hit in this update as well from what I was tracking.