I find this whole topic very difficult. My ds is on the G and T register at school, and, while nobody could deny that he's a very bright little button, he doesn't seem that exceptional to me. I need to make sure that the school is on top of things, and that he isn't allowed to drift - but I did the same with my dd, who is just ordinarily clever. There are a very few (a VERY few) children who are exceptionally gifted or talented - piffle's mathematician or kerrymom's chess player for example, but I do think they are incredibly rare. We need Martianbishop at this point - she has figures.
And I have to say that I do think that it's tactless in the extreme to talk about these children in terms of special needs, when there are children who are doubly incontinent, who can't walk or talk, and who will never lead independent lives. if I had a child like that, I think I would want to machine gun anyone who demanded special need status for their very bright child.
I also think- and I realize that I am going to be shot down in flames here - that there is a tendency to ascribe any problems a very bright child has to their brightness, rather than considering whether the child would have those problems regardless of their intellect.
My brother, for example, always explains his ds's disruptive behaviour by saying that he's bored because he is so much brighter than the reat of his class. He is bright - but he is also a lively and cheeky little boy who needs to learn how to behave - genius IQ or not!