How many times will they change a word that has negative connotations before they realize you can't outrun the euphemism treadmill? The phrase "mentally retarded" was picked because, at the time, it was neutral. If you want meaningful change you won't reach it playing word games. If they want meaningful change they will have to change the way people feel about people who are different from themselves. Good luck with that because people seem to be predisposed to fragment into groups and look down on people outside their group.