stoked82 - 6:29 pm on Dec 17, 2012 (gmt 0)
I am also experiencing a sudden drop in rankings. I noticed a near 40% loss of Google organic traffic on Dec. 14th and it has remained constant since.
My homepage primary keyword is no where to be found in the SERPs. I was listed #7 on page 1. Now I have a less relevant sub page ranking for my homepage primary keyword on page 8. And Google is now ranking spammy or poorly optimized sites ahead of mine which I have been out ranking for over 1 year.
I am also noticing the same issue for some of my high ranking sub pages for their respective primary keywords - less relevant pages are now ranking but at a big decrease in rankings from where the relevant page was last week. But my site has received no unnatural link warnings, it is still #1 for the exact match, and still has #1 rankings for non-competitive keywords. Also, the site was never effected by previous Panda or Penguin updates.
I have no idea what is going on? Anyone else experiencing similar problems? Have you recovered?