Google Panda and Penguin updates always have been one of the fearing factor among bloggers. For many bloggers it bring good news but I have seen majority of people crying after Panda/Penguin updates. Google is looking forward to make search engine more user friendly and to provide accurate information to end users.
They keep rolling their updates to have better control over SERP.
Google launched 27 updates in year 2012 and here is nice infographic representing about every update in a very smart way.
Have a look at it and you will know about it very well.