I think there has been a sharp increase in the number of diagnoses of Aspergers/"high-functioning" autism. Perhaps too many diagnoses. That's a pretty subjective call.
I want to see hard numbers on my son's end of the spectrum, the "hard" cases of autism, the ones with severe language impairment ("Within weeks his language had dried up and he would no longer make eye contact"), not just kids with slightly "dorky" (as you say) behavior.
I suspect there has been a steady increase in the incidence of severe autism--but that's just a hunch. Nobody is studying just one part of the spectrum. And I'm tired of people dismissing the problem as if there is no problem.
How old is your son? I hope you have a lot of support - I know that has been important to us when dealing with our boys.
Instinctively, I disagree, but of course I cannot prove it. Between my husband and I, we have encountered quite a number of people with children diagnosed with Asperger. It is not nearly as common to encounter a child with true autism. In real life, I haven't met one yet.