Kufu - 4:30 pm on Oct 1, 2012 (gmt 0) [edited by: Kufu at 4:54 pm (utc) on Oct 1, 2012]
We have some EMD sites with highly targeted topics, all with unique (well written--it's not Shakespeare but it's well done) content, and most of them have been hit; however, the drops seem to be only for the exact match keywords (mostly).
One particular drop that vexes me is a site dedicated completely to a common error/confusion between two words in English. The domain is wordoneVSwordtwo.com. The site has more information on the topic than any other resource that I have come across. It used to rank at #4 for the keyword, but now it's gone (didn't click past page 10).
Like most Google updates, it looks like the algo doesn't discriminate much when it comes to quality, and just took out most if not all EMDs just because they were EMDs; however, like most (if not all) other updates, sites will get reevaluated, and the ones which suffered collateral damage will float back to their old rankings (and sometimes even do better).
I should say, that not all our domains got hit. Our oldest EMD which is a typesofwidget.com site (again with tons of useful content, and organic links--we never did any link building for these EMD sites, all links are organic), has not lost any rankings, and maintains the #1 position it has had for years for the exact match keyword.
[edited by: Kufu at 4:54 pm (utc) on Oct 1, 2012]