crobb305 - 4:56 pm on Apr 12, 2012 (gmt 0)
I posted this on another thread, but it's just as relevant here:
I think JohnMu made an important point on the Google Groups forum:
"While we have just recently started sending out these messages, they may apply to issues that were already known (and affecting your site's standing in our search results) for a while."
Some of us may be waiting in anticipation of something that has already happened. I saw my rankings drop on overly-optimized key phrases about 6 months ago, and got a message on March 2.