Is There a Google Page Rank Update Going on?

I think Google is in the progress of doing a Page Rank update. I inadvertently noticed a few sites have improved their ranking by one or decreased by one. I haven't read anything about an ongoing update via the better known bloggers, but I noticed their sites haven't been affected like last time, so this should be a fairly quiet update. But I know it's forthcoming soon.

I noticed a couple sites that were 4's are now 3's and one or two sites that were 5's are now 4's and a couple that were 6's are now 5's. One of the interests that operate in the same space I do is now a PR7. A few days ago they were a PR6.

Last year, Google did an update around this same time.
http://www.mattcutts.com/blog/infrastructure-status-january-2007/

Update:
I've also noticed one site had a PR0 and now it's a PR4.
The link:www.yourdomainname.com operator seems to show updated backlinks, too.