I know it’s only been 3 days since I last posted on "Tons of sites going “Supplemental Results"- but I should post an update.
GoogleGuy has posted a few times in Webmasterworld in the thread called "Supplemental club- Big Daddy coming"
GoogleGuy jump in at message #160 with:
I’m happy to ask someone to check this out. Please send an email to sesnyc06 [at] gmail.com with specific domains and the keyword "gonesupplemental". I have a theory about this, which I’m asking the crawl/index guys to check out, but I’ll need 5-10 specific examples to check if my theory holds. If my guess is right, I’ll try to get the crawl/index folks to get things back to the previous behavior.
Then Google Guys Jumps in again at Message #195 with:
Based on the specifics everyone has sent (thank you, by the way), I’m pretty sure what the issue is. I’ll check with the crawl/indexing team to be sure though. Folks don’t need to send any more emails unless they really want to. It may take a week or so to sort this out and be sure, but I do expect these pages to come back to the main index.
This sounds like good news!