As far as I can recall, in my four years of studying communication disorders, Asperger's was under the same category as autism: as a Pervasive Development Disorder, or Autism Spectrum Disorder. However, all PDD's (ASD's) were somewhat interrelated, including Rett's syndrome and Childhood Degenerative Disorder (both of which are far more bleak diagnoses than autism). I believe the reason for that grouping were the qualitative psychological similarities of AS, Autism, CDD, Rett's, and PDD-NOS (Pervasive Development Disorder-Not Otherwise Specified). In other words, a diagnosis of any of these meant that you were on the Autism Spectrum, but it did not mean that you had "classic autism."
Also, one qualitative difference, used for differential diagnosis of Autism, AS, and PDD-NOS was that a person who has AS has had NO UNACCOUNTED FOR LANGUAGE DELAY. (i.e., if you had ear infections while you were little that resulted in language or phonology (speech sound) delay, you still could be diagnosed with AS rather than Autism or PDD-NOS, but if your language was delayed without any known reason, AS would not likely be the diagnosis). If we lose the diagnostic difference between Asperger's and Autism, children who have AS and need services may not get the right kind of services, and become frustrated at working at a level far below their capacity, especially when it comes to language.
However, if what they are saying is that Asperger's, as it's own diagnosis, would be listed under "Autism Spectrum Disorders" rather than listed in isolation, or under "Emotional Behavioral Disorders/Disturbances", then I think it is a move in the right direction. I would rather be seen as a subgroup of "high functioning autistic" than "emotionally and behaviorally disturbed." I am not as familiar with the DSM as I should be, so I don't know how they are currently listed. I only know the groupings of language impairments that I have been taught, and Speech-Language Pathologists don't necessarily work from the DSM.