It seems that Google Authorship has gotten a bit of a shake up recently. According to the data shown by MozCast Feature Graph, a big short-term drop in the number of tracked searches displaying authorship mark-up has made it’s way forward. What could possibly be the cause of this sudden drop in Authorship?
It seems that some people feel that it was foretold at Pubcon by Matt Cutts himself. During the time Matt was speaking, he suggested that an improvement of search quality occurred when there was a 10 to 15% reduction in authorship. Some thought that meant that Google reduced, or will reduce the amount of authrorship mark-up appearing in SERPs.
A column written by Dr. Peter J. Meyers explains in greater detail the situation of the drop in Google authorship, and asks if authorship counts dropped, which searches lost mark-up, and what can be done about it.