From the original article: "Google has refreshed its algorithm, this time with Panda update number 20.
This update would affect 2.4 % of the English queries while other languages have a 0.5% impact that's rarely noticeable. Panda 20 update went live on September 27th, 2012.The first Panda update went live on February 2011.
What to do next?
You don't need to panic with this update. This refresh has been done to improve the quality of search results so your strategy as a search engine optimizer would be to present the most relevant content to the user in an appropriate manner. Its better to stop overdoing seo and take natural steps towards making your website look genuine. Concentrate on adding fresh content to the website as Pandas love fresh content."
Via Robin Good