Matt Cutts, head of Google's Webspam team, officially announced last night via twitter the release of Panda 4.0, the most recent iteration of their content quality algorithm.
Google is rolling out our Panda 4.0 update starting today.
— Matt Cutts (@mattcutts) May 20, 2014
Cutts also took the opportunity to confirm an over-the-weekend update to their Payday Loan algorithm, which deals with extremely spammy niches.
Chatter and Predictions
There has been chatter across the web all month about potential updates, shifts, and spikes. Barry Schwartz at Search Engine Roundtable wrote several articles outlining the possibility of Google preparing for a large update (Panda 4.0) and ranking shifts being reported, earlier this month.
Dan Petrovic of DejanSEO also reported his Algoroo showing signs of a potential update, prior to the official announcement of the Panda update. Dr. Pete of Moz also reported Mozcast showing signs, prior to official announcement.
— Dr. Pete Meyers (@dr_pete) May 20, 2014
News, Analysis, and Discussions
This morning Dr. Pete posted his initial analysis to the Moz blog, also detailing eBay's recent plummet in SERP rankings. To further eBay's online woes, it appears a database containing user's passwords has been hacked. They're now requesting all users to change their passwords.
Search Engine Watch and Search Engine Land both have coverage of the Panda and Payday Loan updates as well.
SEW reports that some sites are already seeing large recoveries from previous Panda issues. SEL has in-depth coverage of the Payday Loan update as well as a history of the previous updates, and report that the overall impact of Panda 4.0 affects ~7.5% queries.
Marcus Tober of Searchmetrics produced a quick analysis of the winners and losers of Panda 4.0.
Trevin Shirey covers the potential problems, issues, and risks of Panda as well, providing a real world example of Panda negatively affecting a legitimate business.
An SEO discussion thread concerning Panda 4.0 can be found over at Inbound.org.