The ongoing WebmasterWorld thread has a lot of ongoing chatter about updates since December 10th but yesterday that chatter picked up a bit, which may imply there was an update yesterday.
I never heard back from Google on my December 10th report but I will ping Google again about this specific report.
Here are some one liners from the thread from yesterday:
Down 40% compared to yesterday. No changes on my side.
Traffic down by about 10% compared to last week
I am seeing a nice increase in rankings and traffic. Started yesterday.
Today’s number 1 for my main two-word key term doesn’t have the exact term on the site.
Like always, some winners and losers.
Checking the statistics out there, only one has updated so far and it was MozCast showing a huge change yesterday:
Update: SERP Metrics also shows signs of an update. And now SERPS.com also shows sign of an update.
Update 2: At about 2pm EDT Google told me this is not Panda related but they are going to dig deeper and let me know if it was something else.
Update 3: December 17th, Google said they are not aware of any update.
Update 4: See my official dreamer post. Did you notice a change?
Forum discussion at WebmasterWorld.