Some interesting facts from that Boston Globe piece I just linked to:
[C]oed bathrooms can be found in the dorms of some local universities, and in some cases students have been allowed to redesignate bathrooms on their floor. At Hampshire College in Amherst, bathrooms in student ”mods” (apartment-style suites) have been coed since the school opened in 1970. Amherst College allows students on a dormitory floor to designate their bathrooms coed, said Paul Statt, director of media relations.
And at the University of New Hampshire in Durham, undergraduates can voluntarily create coed facilities, said Scott Chesney, director of residential life.