Do you remember when being special was a good thing? Me neither. Well. . .barely. Thinking about the word "special" makes one realize the danger of euphemism. People want to be considerate of others with, let's say, non-standard abilities. Realizing the negative connotations of words like "retarded" or "handicapped," well-intentioned folks adopt phrases like "special education" or "special Olympics" to denote services and programs designed for these "differently abled" individuals. There's certainly nothing wrong with that--on either an ethical or definitional level. The literal meaning of "special," after all, is simply "of a distinct or particular kind of character." In that regard, these people--any people, really--certainly are special.
The problem, of course, is that using the word "special" to "euphemize" something with negative connotations does nothing to ameliorate people's attitudes towards the underlying realities. Instead, it simply makes the euphemism negative. Words do have power, of course, but attempting to improve social attitudes through linguistic engineering puts the cart before the horse.