It was in last month November. I don't remember exact the Date. But I'm sure it was in the second or third week of the November 2009.
Google last updated their Pagerank on October 30. Pagerank is not an important factor, so don't focus on obtaining a high PR.
Are you referring to the PR toolbar update? If so it was October. If you are referring to Google itself, it updates daily.
Major adjustments for PR was on 30 Oct, after that there are a few minor adjustments affecting a few websites, downgrading the PR.
PR is a major factor, but you should not concentrate on building a high PR website. Simply build a website with a lot of content, and the PR will flow naturally.
This thread is about the MAjor PageRank Update. It was on October 30th-Nov 1st as all datacentres need to be updated with the changes. Here is some info on it : Google’s Major Pagerank Update
Can any body tell me how shall you identify that Google has gone updations in itself...It would be more interesting to know about this..