A few people around the forums are starting to see some major ranking changes on both Big Daddy and non-Big Daddy datacenters. I haven't had time to see if any of mine have been affected yet, but just wanted to alert everyone to be on the lookout for a possible shakeup.
UPDATE: Of all my sites, only one has had signifcant changes to its rankings today. It is a site that lost nearly all of its rankings back on October 17, 2005. I haven't touched the site since, yet it regained all its rankings today. Looks like whatever filter was applied back in October has been loosened up today.