diberry - 5:19 pm on Aug 2, 2012 (gmt 0)
We have actually seen a slight uptick in traffic over the last 2 days on a Penguin-effected site. Not much, but 15-20% increase of normal (post penguin) daily visits from G*.
Since the Panda update on July 29th, I've seen a steady increase on my Penguin affected site. What's changed is that a lot of my backlink sites appear to have gotten a boost - suddenly they're showing up higher in my referrals than they have since before Penguin.
I think Penguin and Panda set off chain reactions: Site A falls afoul of them, so suddenly its outbounds lose value, and every site they linked to is affected slightly. If a bunch of your inbounds - or even a bunch of your inbounds' inbounds' inbounds get affected - then so do you. That might explain why it can be so hard to tell what's gone wrong for your site, or why or how to fix it.