Watch the video here: http://www.internetmarketingninjas.com/blog/google/pandaupdate/panda-4-2-what-is-google-panda-are-you-safe-part-1-jim-ann-show/
What is Google Panda update? How do you diagnose if your site might have been hit by Google Panda? Here's what we've been talking about at this week Jim and Ann show!
Google has been talking about those "rolling" updates for a while: This one is confirmed to be rolling out over the course of a few months - which means that if you were affected by this update you are probably not going to see it overnight.
Instead, there will be a slow decline which you'll be able to spot only in a few months - which makes it harder to diagnose what happened: Panda update? Penguin update? Above the fold update? Mobile update?