The New York Times claims "At the Summer Olympics, the marathon will be the
only foot race measured by the standard system instead of the metric system."
http://www.nytimes.com/2012/04/21/sports/the-marathons-accidental-route-to-26-miles-385-yards.html
I have e-mailed them advising them of the need for a correction. Although the
official length is clearly derived from 26 mi 385 yd, that actual official
length is 42.195 km, and the rules require it to be measured and marked in
kilometers.
I guess they are die-hard Imperialists.