Ralph_Slate - 2:37 pm on Oct 15, 2012 (gmt 0)
aristotle, I believe that I have recovered from a Penguin penalty - or some other penalty that was imposed on April 24.
I am no longer seeing my site repressed in the SERPs. My site is long-tail, so people searching for pages on my site's subject should get my site on the first page when there is no other competition. From April 24 to Oct 17 that was not the case - my site often appeared at the #11 position, which was a clear sign of a penalty to me.
Starting on April 18, when I search for the phrases that I've seen repressed, they are now showing up in the #1 or #2 spot.
I made a lot of changes since April 24 - but because my backlinks were all legit, I did not focus on backlink removal, with the exception of a small handful of sites which had linked me blogroll style to their message forums so it showed 400,000 links on their site to one on my site. That seemed really egregious, so I asked those sites to remove the links. A couple did, but they did it months ago, so it didn't coincide with Oct 18.
I suspect that the penalty might be time-based, and could be due to something else I did, or maybe just due to an increase in seasonal traffic that my site gets from October to April - maybe the increase in traffic pushed me above some threshold that Google uses.