Google Panda Update 20 Rolls Out

Google has rolled out a Panda algorithm update on September 27, 2012.
This is not exactly a data refresh, in fact it’s an algo updates to the existing one. This is Google Panda 20, because this is the 20th Panda update so far.
This is a quite major update impacting 2.4% of English search queries and is still rolling out, for the next 3 to 4 days. Matt Cutts has confirmed this news to SearchEngineLand via the below mail -
Google began rolling out a new update of Panda on Thursday, 9/27. This is actually a Panda algorithm update, not just a data update. A lot of the most-visible differences went live Thursday 9/27, but the full roll out is baking into our index and that process will continue for another 3-4 days or so. This update affects about 2.4% of English queries to a degree that a regular user might notice, with a smaller impact in other languages (0.5% in French and Spanish, for example).For your info, the last Panda update was on Sep 18 and it affected <0.7% of search queries.
CONFUSION: On the very next day, September 28, Google has also released an algorithm update for exact-match domain, which will demote the low quality exact-match domains from SERPs. And, it affected 0.6% of English-US queries.
Now, lots of webmasters are noticing huge drop in traffic. But many are not confirmed, whether it is due to exact-match domain or Panda 20 update. Because both algo updates were released almost simultaneously (1 day difference).
P.S. - Even though you have an exact-match domain name, if you have thin content or low quality content in your website, penalty by Google Panda is most likely.
Facebook announced that it will add some improved features and an user friendly looks for the messages.