A Panda refresh 3.7 was on the role last weekend and the news has been confirmed by Google. The refresh began on June 8th and affected less than 1% of search queries in the US and about 1% global queries.
It was just a data refresh of the Google Panda algorithm and there were no algorithm changes. SEO forums were abuzz with discussions about the update with webmasters commenting about their rankings. Some were complaining about the lost rankings, but most said the refresh had no effect on the position of their websites.
Panda update 3.6 happened on April 27 and 3.7 has come a bit more than a month after it. 3.6 was a limited update as well which did not affect many sites.Google Panda Update 3.7 Rolled Out on June 8th!,