Google have confirmed that the latest revision to the contentious Panda update - codenamed Panda 2.3 is now being brought online. As a result of this, some rankings will fluctuate and may end up significantly worse, or better than they were before.

From recent experience, I've not really noticed and major changes in rankings for sites that I am monitoring, so perhaps the people who are most vociferous in denigrating Panda are those that indulge in grey-hat SEO.