It has been a month since penguin and I've noticed these things: -Sites that I limited keyword stuffing to 300+ keywords per post got hit hard. -Sites that I limited keyword stuffing to 100 keywords max didn't get affected at all. These are on pages with 500+ words of content. I'm pretty sure the max on keyword stuffing would be lower if I had less content. Conclusion: Keyword stuff still works and Penguin must be analyzing the ratio of keywords vs real text? If the ratio is too odd, you get penalized. So, keyword stuff a little bit but not too much.