A good number of the domains that were sent to me were not exact match domains. At first I was struggling to figure out why Google would consider these EMD's and demote them. But now I see that for many of these, Panda is probably an issue.
If your website traffic has been affected this week I would highly recommend looking at your site from a Panda perspective. Here is some information about Panda:
Google Panda Update - History, Diagnosis and Recovery. Panda affects sites that have pages with thin content (i.e. only a few sentences) or content that is duplicated either on your own site or on other sites across the web. There are other on page factors such as spelling and grammar. (See the post referenced above for more.) It is important to note that Panda is not about backlink quality.
I hope this is helpful. You can recover from Panda by removing duplicate content and adding more valuable content. We tend to have a Panda refresh about every 3-6 weeks. If you correct your Panda issues you should be able to recover with the next update.