My buddy Zack Williamson has worked on some major tube sites in his career as a porn seo, he posted his theories about the pending penguin updates on his blog, figured some of you might be interested.
"After months of no updates, Matt Cutts lets the cat out of the bag on the newest webspam change? Penguin 2.0 is coming and it will have serious implications for link buying and therefore porn SEO. Since 80% of the top porn tubes spend tens of thousands buying links, expect to see big shuffles in the SERPs."
More here:
http://zackwilliamson.com/penguin-2-0/