Robin Good: Last Tuesday Google has released a new ranking-factor algorithm update focusing on eradicating more webspam from the SERPs.
More info here: http://searchengineland.com/the-penguin-update-googles-webspam-algorithm-gets-official-name-119623
and here: http://www.seroundtable.com/google-penguin-impact-poll-15081.html
Reconsideration request form: http://www.webpronews.com/google-penguin-update-reconsideration-request-tips-from-google-2012-04