Ever since this past Friday, Google, Inc. has been in the process of updating its Pagerank value. Also known as a PR update, this process of updating Google's toolbar (the little green bar) typically takes anywhere from a few days to a week. It usually occurs every three months or so, but has been quite sporadic over the past year or so.

The update is not done propagating, so different Google datacenters are showing different PR values. However, you can view an extended sampling of datacenter values by using the handy little tool at:
http://www.seochat.com/seo-tools/future-pagerank/