Panda 2.3 is now live

Previous Panda Updates
So far, the Panda update schedule has been like this:

Panda Update 1.0: Feb. 24, 2011
Panda Update 2.0: April 11, 2011 (about 7 weeks later)
Panda Update 2.1: May 10, 2011 (about 4 weeks later)
Panda Update 2.2: June 16, 2011 (about 5 weeks later)
Panda Update 2.3: July 18th, 2011 (about 4 weeks later)

The 2.1 to 2.3 dates are approximate. Google may have rolled them out just a bit earlier or later than those exact days. The bigger issue is that you can see a trend developing. About every month, Google reruns its Panda algorithm.

Official: Google Panda 2.3 Update Is Live