I've been seeing posts and forum complaints that Google Analytics has shown tremendous drops in search referrals from Google Image Search. To make a long story short, Google Analytics seemed to have switched how they report Google Image search traffic, moving it from the referrals report and into the organic search report.
Here is a graph from Gabs:
I was able to verify this in several of my sites that I track.
Google, I do not believe, has any word about this change, so I can see why people freaked out when they saw this.