We've been seeing a lot of Penguin related chatter recently, specifically around Penguin 3.0 launching, with several slow pushes on that algorithm through the past several weeks. We saw a huge spike around that over Thanksgiving, which they confirmed and yesterday what we saw on Thursday, seems to have been rolled back.
Yesterday in a Google+ hangout, John Mueller of Google addressed two questions related to Penguin.
(1) Penguin is still rolling out, he said 23 minutes and 54 seconds into the video. He said essentially, it is still rolling out and the team is being very cautious about the rollout.
(2) He was asked if Google would give formal notification when Penguin is done and completed rolling out. John answered that 49 minutes and 25 seconds into the video saying he isn't sure. He said, to some extent, "we're hoping that these things will keep updating." He is hoping it would turn into a rolling update. Maybe? Is that a hint that Penguin will never end and continue to roll? I don't know - he doesn't seem too confident in his answer. Here is the video:
Forum discussion at Google+.