Google has publicly posted the first comments about the Penguin update.  Pierre Far shared the following on Google+:

On Friday last week, we started rolling out a Penguin refresh affecting fewer than 1% of queries in US English search results. This refresh helps sites that have already cleaned up the webspam signals discovered in the previous Penguin iteration, and demotes sites with newly-discovered spam.

It’s a slow worldwide rollout, so you may notice it settling down over the next few weeks.

We noticed that it seemed to be rolling out slowly, and hit internationally first before it went to the US on Sunday morning.

Only less than 1% of US search query results were affected, which is much smaller than I would have anticipated after such a long wait for the update.  By comparison, Penguin 2.0 impacted 2.3% but the Penguin 2.1 refresh only impacted 1%.  The original Penguin impacted 3.1%

The slow rollout could last for a few weeks, despite John Mueller earlier saying that it had completed in a Google Webmaster Office Hours.  He later said that it looked like it was still ongoing.

One thing worth noting is the confusion between whether it is an update (Penguin 3.0) or a refresh (which would be Penguin 2.2).  In the headline of Far’s post, it is called a Penguin update, but in the body, he calls it merely a “refresh” and not an “update”.  It does have all the signs and impact of a regular update – especially as Far states it helps sites that have cleaned up from previous Penguins and impacts sites that have now been caught.

For full details on what was impacted, read our full coverage: Penguin 3.0 Finally Updates – Google Hits Homepages, Affiliates & 301 Redirect Spam