Only changes I can see is to the PR of dropped domains. G is just tidying up some aspects of site PR IMO.
My PR wasn't affected, but my SERPs were smashed! There are also threads about this on the Warrior Forums as well so something is seriously going on with Google at the moment.
So what's up with the N/A? looks like one of my website index is stuck with N/A and all the other pages are PR4-5.
Next PR update wasn't due until end of June, put the way google chops and changes it wouldn't surprise me if they have updated already
Pagerank dropped on 1 site, up or unchanged on others. SERP not changed. Also, they are now showing soft 404s in webmaster tools which I believe was the reason behind the one site that lost PR.
btw Who told you that PR will be updated for ALL sites in the universe at the same second?! May be PR is updated every month for 30% of the sites, or every day for 5% of the sites.