In a post at the SearchEngineJournal.com, they discuss if having a keyword in the domain name that relates to the topic your trying to get a search engine ranking for, helps you get a better position.
The basic conclusion is that in Google not so much.
In Yahoo somewhat more and in Microsoft Live Search, Yes.
“”””if you are targeting Microsoft and Yahoo in your search marketing campaigns, then you should probably have a domain name that has your targeted keyword in it, especially in Microsoft Live Search””””
The author goes on to state:
“””””””Yahoo has been reported to take into account domain name keywords in the past, but recent search results suggest that less emphasis is placed on domain name keywords, which has helped filter out keyword-stuffed and spam-riden sites with low quality content.
MSN Search apparently does take into account domain name keywords. As an example, compare the results of “cheap travel” on MSN Search and Google. You will notice that the MSN results are dominated by keyword domains containing the keywords cheap and travel, while Google results are not.”
So to boil it down, keyword in domain names are not important for Google, moderately important for Yahoo and it is somewhat a major ranking factor when it comes to MSN / Live Search”””””
An interesting read that you should check out.