Interesting post by an expert SEO who is also a domainer, as to the value of exact match domains for domaining (amongst many other interesting things):

Exact match domains are great when there is NO COMPETITON, and they are great when there is SERIOUS COMPETITION. Anywhere in between, the vaue ad from exact match is not so significant except as it pertains to exit strategy and other business factors. Business people know value, and we need to recognize that or if we have better ideas, PROVE them not speculate about them.
? Live Blogging T.R.A.F.F.I.C. East, New York - John Andrews - johnon.com

Exact match domains are helpful, but they certainly aren't the be all and end all for SEO.