In general, Janik says that many of the "quality old sites that we love and nurture suddenly disappeared from the top ranking positions to pages in the tens or twenties of the index. This very unfortunate fact sent many SEO's into panic mode."
A number of users also reported seeing results that were less-relevant for simple queries, and newer Web sites seemed to take a bit longer to load. Meanwhile, other site owners reported problems with cache data. "(It) was not showing up accurately even though index reports were showing otherwise," Janik says.