I am doing my own research to find more about the recent update (I know most of you are also doing the same). It's definitely not about anchor density this time. My sixth sense says it has to do either with DA or PR. I am taking a poll to gather as much information as possible. I hope the BHW community with help me out.. Please participate actively guys. I will surely publish a report on BHW on my findings. Has a website with PR 3+ got hit by the recent Penguin 2.1 Update? If one of your site was hit, what was the Page Rank ?