Reading through this paper, I think the results are more indicative of the inappropriateness of the current diagnostic criteria for diagnosis of adults with Asperger's. The symptom profile of individuals with Asperger's changes over time (this is reflected in the data) but interpreting that as "outgrowing" the syndrome doesn't make sense. Asperger's is a developmental disorder which means that a person with Asperger's will develop differently, but they will still grow and change. What doesn't change are the underlying differences in how the person perceives and processes information about the world.