"Erase the R-word" the big billboard advertising the Special Olympics screamed. I would guess the "R-word" being referred to is "retard," used as a pejorative noun, derived from the adjective, "retarded," as in "mentally retarded."
"Retarded" is a euphemism, a nice word for something we want to pretty up, like "sex worker" for "prostitute." The problem with euphemisms is that they still have the same references, which means they soon acquire the same connotation. Today's euphemism is tomorrow's epithet. The new euphemism for "retarded" is "special," which has already gone down the garden path.
But I don't think words are the problem--or the solution. The problem is attitudes; there are always going to be people whose egos require them to insult and belittle other people, but it doesn't mean we have to pay attention to them, and we certainly don't have to overinflate the English language to try to counteract them.
My take? I think Special Olympics should save its billboard money and invest in more ribbons and trophies instead.