maddawg - 2:04 am on Apr 17, 2012 (gmt 0)
I'm seeing the same thing. It's not just about "anchor-text being devalued" based because websites with natural, high quality, but overly repetitive anchor text links (guest posts, widgets, high quality press releases, etc) are still ranking high.
Websites that manipulated rankings thru low quality, high PR keyword-rich anchor text are all getting hit. It seems to me that the site's recent link acquisition rate is really what tripped something.
This has always happened in the past but it seems like google is emphasizing this even more than it used to. I can't help but think this is part of their efforts to prevent overly-SEO'd sites from dominating the rankings.