Relative prevalence of savantism 

This may be a tangent to a previous discussion, and I was going to place it in Autistic Savant, but this article seems to get more attention -)
Is there any research that demonstrates that savantism is more prevalent among autists than in the general population? It seems to me that non-autistic people can have extraordinary abilities as well, and those might go underreported as they're not as interesting as the autistic savant.