aristotle - 8:17 pm on Sep 18, 2012 (gmt 0)
any Penguin Update is still in development and not launched into prime time so far.
Isn't it possible that Google is doing some live testing of a new version of Penguin for short periods of time and/or on a subset of data centers? Or does a new re-run have to be rolled out everywhere all at once?
Anyway, I've seen a couple of things in my logs that cause me to suspect that some live testing is in progress. But of course there's no way to be sure.