If you’ve felt a little over run in the last little while by the Google zoo which has been running over the index, it’s a tad sorry to report but we’re not quite out of the wild yet.
Google has mentioned that while the Penguin algorithm shift is targeted at removing/reducing the spam sites in the results, they have also let it be known that it’s still actively being adjusted and worked on. The Penguin update is acting as an adjustment (their word) to the results in removing the backlink value that spammy sites could pass on to those looking at making a quick buck or shift in their positioning. As for Panda, that was the content upgrade in case you’ve forgotten, it is still tuned for digging out poor content on sites and pages. And although the updates are coming more consistently with them being automated, the shock, and surprise that website owners were initially experiencing from positioning drops, have lessened.
Panda is a regular monthly addition now to the search index, and Penguin is being incorporated in much the same way, however it still has a ways to go. With the addition soon to your webmaster tools to handle unnatural links pointing to your website, there will undoubtedly still be some site owners experiencing a shift in rankings if being inattentive with their site. Over time however, it will be a part of the regular indexing, and the results will be cleaner for it.
Matt Cutts on the growth needed of Penguin:
If you remember, in the early days of Panda, it took several months for us to iterate on the algorithm, and the Panda impact tended to be somewhat larger (e.g. the April 2011 update incorporated new signals like sites that users block). Later on, the Panda updates had less impact over time as we stabilized the signals/algorithm and Panda moved closer to near-monthly updates. Likewise, we’re still in the early stages of Penguin where the engineers are incorporating new signals and iterating to improve the algorithm. Because of that, expect that the next few Penguin updates will take longer, incorporate additional signals, and as a result will have more noticeable impact.