I'm not sure this is related so much to changes in the algo or just my site, but: my site hit by Penguin 1 is now holding steady with higher levels of Google traffic than it's seen since that fateful day. Not wildly higher, but I have recovered a good bit on a few of the search terms I lost that day. Like, I used to be #1 and now I'm #3, or I used to be #3 and now I'm #5-6.
The keyphrases I have NOT recovered on all happen to be related to one of the niches in those top links Google has separated out (the links to images, maps, shopping, "more"...). I'm beginning to think that's part of the mystery, and I'll probably never recover significantly on those because Google's just handling them differently now somehow and there's no going back.
All in all, I'm pleased. It seems like every month, I get a little boost of a hundred or so more visitors from Google per day. Maybe they're letting me out of Penguin incrementally or testing something?