Whitey - 8:05 pm on Feb 14, 2012 (gmt 0)
Google had indicated that it would turn the dial up on the quality score for Panda mid last year. I wonder if this is it.
If so it makes some recoveries vulnerable, and unaffected sites the same.
It also seems that these reports of Panda like shuffles are going over extended periods, again morphed into the main algorithmn. Still no confirmed clue until Google reveals what's going on.