Actually, Mic, someone round here (Can't remember who it was, to give credit where it's due, sorry) said much the same thing re: speech development.  An autistic kid might start out with pure echolalia, repeating phrases as they're heard, move on to more refined echolalia where they repeat phrases in more appropriate settings, then to using stock phrases as a means of basic social interaction and self expression, and eventually full self-expressive speech.  So, does it MATTER that they developed speech differently and maybe a bit later than a "normal" kid, if they get the same end result basically?