Solid answers are in very short supply. Reports of recovery are so rare that they may not really be Panda recovery at all.
One thing is clear. Panda's target is not any particular type of site. Instead it is Google's first step into measuring "quality" in addition to "relevance". It's a brave new world and a major focus for the coming year, according to Matt Cutts. This recent update was over a year in development, so we know it's not a casual turn of any previously existing dial.