I think this is an interesting post by Grancran over on the official forums. We've already talked about how Blizzard is revamping the newbie experience in upcoming releases (including the next patch and the expansion), but he wants to know: for whom? Sure, there are going to be lots and lots of people going through the starting experience again when the expansion rolls around, both because of the new class combinations and the new races, but all of those people have already played the game. Why update a tutorial system when the majority of gamers have already played WoW?
It's an interesting question. Neth answers pretty tamely, saying that we were all noobs at one point, and that they want to make the starting areas as welcome as possible. But the question remains: is Blizzard expecting an influx of new players at some point in the future?