I also think it is ironic that I was speaking to my adsense for search rep the other day and they were saying how much they loved eHow.
So the algo that was the eHow killer has turned out to be much more than that - the clamour to downgrade "content farms" by webmasters has created the Panda algo.
Unfortunately Google always have to go one extra step - algorithmically rather than manual and have spent the last year working out how to downgrade these type of sites using technology.
As usual it is crap and takes out several thousand real sites (not mine - I have a few thousand that are jumping up nicely with no content, I accept I am an affiliate and it is up to me to work ahead of the game).
Why not just employ quality raters and manually downgrade domains that are mass content farms. Would have taken about 5 hours with a few guys manually doing that. You could even be crazy and employ a few of them ongoing and keep on top of it.