Can't remember when this month, but a few days ago my backlinks dropped 500 in webmaster tools perhaps this is an indication Google is planning to update PR.
Had a few keywords change significantly - alot of instability. My most desired keyword is up 30 one day ... down the next. Fortunately, long tail results still holding.
some areas appeared to have reduced value in regards to affecting PageRank. These areas include the following aspects:
1. Multiple links from the same site or run-of-site links.
2. Links with text around them that indicate they are purchased such as “Partners”, “Advertising”, etc.
3. Links from sites that hold little relevancy.
Besides, Google Webmaster Tools also underwent several changes:
1. Reduced Link Count
2. 301 redirected URLs do not appear in the link list