We must be close if Google is actively working on their announcement for when Penguin 4.0 goes live.
John Mueller of Google said this at the 44:30 mark into yesterday's hangout on YouTube Live. He said "we are working on an announcement for that there, so like when it's ready we will let you know."
That means, Google is already working with press and whomever to make sure they get the Penguin announcement clear and right. John then answered if the Penguin announcement will come before or after it goes live and John said "I don't know about before but we will try to get the the timing so that we don't confuse everyone."
So clearly, Google is taking this Penguin release seriously and if they are working on the announcement, it has to be coming fairly soon?
Forum discussion at Google+.