They did it! They managed to get approvals to run an Olympic-distance triathlon in the monumental core of Washington, DC on September 16, 2006. Congratulations to the organizers on what must have been an enormous task juggling numerous agencies and government entities.
Registration is open here. It will set you back about $183 to get in. I think I'm going to wait-and-see this year, and perhaps give it a go next year if it survives. If they get rainfall anywhere in the Potomac watershed within a day or two preceding the race, I think they probably will have to cancel the swim due to water quality issues. But let's hope it goes!