AlyssaS - 10:09 pm on Oct 15, 2011 (gmt 0)
I think the issue is that Panda only appears to be run on some of the SERPs - I'm guessing here, but major keywords, plus perhaps top 20 of others. So every time Panda demotes stuff, new dross that wasn't assessed surfaces.
What really needs to happen is that they run it every day because that way everything would be assessed rapidly and they'd deal with new rubbish in a timely manner. After several thousand iterations, they'd probably get a good handle on what was good and what not so good. As it happens we've only seen a total of 7 iterations.