Re: The timing of this article is funny
"Yesterday I was looking through news.google.com and was wondering to myself if it would be possible to filter *out* all of the Washington Post stories."
With the exception of the main news.google.com page, yes.
You need the "GreaseMonkey" add-on, and the "Google Hit Hider By Domain" script.
On google finds, it adds a [block] button on each entry so if blocked, you'll never see anything from that domain ever again. Unless you manually edit it out of the blocked list.