When's the last time you saw the Aspie birth rate exceeding NT?
Uh-uh. No, we're not going to win out in natural selection.
However, societies (composed mostly of NTs) with autistic genetics in their gene pools are probably more likely to survive than societies without autistic genetics. Autism is common all around the world, so it's safe to bet it's been with us as long as humans have been around; or else any groups without autistic genetics simply aren't around anymore. Autism runs in the same families as intelligence, creativity, mechanical aptitude, musical aptitude, etc. (also in the same families as mental illnesses, homo-/bi-/a-sexuality, extreme introversion, and eccentricity--that is, all the human extremes).
Autistic people are not superior, as far as natural selection is concerned, because we do not have more babies. However, the traits that are common in autistic people, if introduced into a society's gene pool, will be beneficial.
I think perhaps that the same genetics that make us autistic also make humanity a tool-using, problem-solving, pattern-recognizing species. When concentrated, they cause autism. We're the extreme end of the human spectrum, not a new sort of human.