Google has introduce panda update in 2011 and penguin update in 2012. These changes in Google algorithm are very good for those sites that have quality contents and natural links.

Yeah i agree with you,before updates some people do black hat seo and they were on the top positions but after updates we see only good sites on the top results.I am very happy with these updates and my site rank is improved after these updates.......

agreed and penguin will help quality site to rank on the top and get better reputation.

I appreciate this step for creating penguin update for effective ranking and remove fake links.

Yes these updates are good for those sites which expect good ranking and have low due to the fake work of the other sites.

Agreed! Google Panda and Google Penguin, both algorithms are really helpful to increase quality of Google. It also helpful to stop duplicate content stuffing and spam activities.