Todd Malicoat wrote an interesting article about the exact match domain update for SEOmoz this week. In that, he points to a Webmaster Help video from Google's Matt Cutts from early 2011, where he hinted that Google would be "turning down" exact match domains as a ranking signal. Here's what he said exactly:
"We have looked at the rankings and weights that we give to keyword domains and some people have complained that we’re giving a little too much weight for keywords in domains. And so we have been thinking about adjusting that mix a little bit and sort of turning the knob down within the algorithm so that given two different domains, it wouldn’t necessarily help you as much to have a domain with a bunch of keywords in it."
Malicoat also points to an article from Bill Slawki from last year looking at a patent for Systems and methods for detecting commercial queries, which talks about exact match domains.