Pagerank is "jumping" up and down.. An update?

Over the past few days and today we can see the values of page rank are "jumping" up and down. Sometimes we can see zero values of pagerank at some web sites and pages that used to be higher than zero. This is quite a strange behaviour of pagerank..
Anyway, it is very possible that Google.com has begun to update page ranks again. We will post further updates here when they are available.