From the original article on WebProNews: "Google has already launched another Panda update. By already, I mean since the Penguin update.
After the Penguin update was announced, and Searchmetrics put out its lists of winners and losers, Google revealed that there had actually been a Panda update a few days prior, and that this was strongly influencing those lists.
The update reportedly hit on Friday, April 27. With all the Penguin chaos out there, one has to wonder how much the Panda update has skewed webmaster analysis.
Barry Schwartz over at Search Engine Land reports that he has confirmed as much with Google, sharing the following statement from the company:
"We’re continuing to iterate on our Panda algorithm as part of our commitment to returning high-quality sites to Google users.
This most recent update is one of the over 500 changes we make to our ranking algorithms each year."