aristotle - 4:09 pm on Aug 17, 2012 (gmt 0)
From Matt Cutts' latest clarification at seroundtable:
we're still in the early stages of Penguin where the engineers are incorporating new signals and iterating to improve the algorithm. Because of that, expect that the next few Penguin updates will take longer, incorporate additional signals, and as a result will have more noticeable impact. It's not the case that people should just expect data refreshes for Penguin quite yet.
This sounds like something that was rolled out before it was ready.