Good point mrsavage.
I had one site go up 100% with Panda 2. 2 months later it dropped to 20% below pre panda levels. So google has placed the site in 3 different categories since the pandas started, normal traffic through panda 1, double traffic with panda 2, and down 60% with some later panda. I didn't touch the site the entire time. I even talked on here on how this site gained massively with panda, now it's no longer true.