Google May Be Pushing Out A New Update: Possibly Penguin?

I am seeing very early signs of another possible Google update both based on chatter at the WebmasterWorld and in other forums and social media spaces. I am also getting private data shared with me by those who are tracking this closely.
Update: Google tells me this is not Penguin or any spam quality control change.
The feeling is that Google is testing a new Penguin refresh and that it may be rolling out slowly. Or that it might be something else. So you know, we had a Panda 4.0 update last week, and then last weekend (before Panda 4) we had a Spam algorithm update. Prior to that we reported on tons of ranking shifts which Google denied despite all the signs of an update.

Google Test Lab For Experimenting With Google's Rankings

Rand Fishkin, the co-founder of Moz, announced on his personal blog a new thing he is playing with he named IMEC, aka Internet Marketing Experimental Collective.

The goal is to increase the number of people experimenting with Google's search results, so they can give more validity to the experiments they run. Rand said, "The goal is to assemble a group of marketers who care about producing high-quality, consistent, repeatable experiments in search engines and on social media to learn more about how these platforms work."

Here is an example of an experiment one would run: