Google is calling their latest Penguin 3.0 release an algorithm refresh rather than an update. According to Google they didn’t add any new signals to the algorithm but rather cleaned up some old issues from Penguin 2.0.
Google broke the story through Search Engine Land that this worldwide rollout had started late on Friday night, October 17, 2014. After some confusion regarding the end of the rollout, it has been stated that Penguin 3.0 is still rolling out and will do so for weeks to come.
A couple other fun facts about Penguin 3.0 is that have been stated by Google representatives is that it impacts less than 1-percent of the English language search queries and it is targeting spammy links. What are the unstated facts? Like all refreshes or updates, it may take weeks or months to figure out the nuances.