Is it possible that Panda 3.0 just rolled out (as of May 6, 2011)? Perhaps it's in the process of rolling out? I'm seeing a massive shake up in the search niches that I monitor, results are bouncing all over the place. My websites seem to be slipping again to a new all time Google referral low.
I've gone through my sites with a fine tooth comb. No link exchanges, no purchased links, no duplicate content, high quality original articles only (many of which I researched for weeks), aged trusted domains (some of which I paid tens of thousands of dollars for), etc. I deliberately stayed away from the SEO techniques of the day and just attempted to drive traffic to my sites through the long slow steady process of adding new content.
Has anyone recovered from Panda? I've been a full time webmaster for 10 years and I cannot for the life of me figure out where my sites are in the "wrong".