The ongoing WebmasterWorld thread has been tracking Google updates and several SEOs there believe that Google is doing a Panda refresh, which would take us to Panda version 3.7.

Google has not confirmed a Panda refresh.

The last Panda refresh was Panda 3.6 on April 27th so we are due a new Panda refresh any time now.

Also note, we had our first Penguin refresh last Friday night / Saturday morning.

One senior member at WebmasterWorld said:

Others reported other fluctuations in the search results and claiming it looks like Panda.

Past Panda Updates:

Panda 3.6 on April 27th
Panda 3.5 on April 19th
Panda 3.4 on March 23rd
Panda 3.3 on about February 26th
Panda 3.2 on about January 15thPanda 3.1 on November 18th
Panda 2.5.3 on October 19/20th
Panda 2.5.2 on October 13th
Panda 2.5.1 on October 9th
Panda 2.5 on September 28th
Panda 2.4 in August
Panda 2.3 on around July 22nd.
Panda 2.2 on June 18th or so.
Panda 2.1 on May 9th or so.
Panda 2.0 on April 11th or so.
Panda 1.0 on February 24th

I will try to get confirmation on this possible Panda refresh and update this story and post a new one on Search Engine Land, if Google confirms it.

Forum discussion at WebmasterWorld.

Update: Google told me there was no such update.