Who did his evaluation? I am very confused, the parent is usually the first one to notice and knows all about the autistic issues. This is very odd. Did the school make this diagnosis? If so, it is highly questionable to me. I work as an educational advocate, and generally, my job is to help parents get their kids what they need because schools won't do it.
Here are the questions I would have for you:
Why was he evaluated, who did it, who suggested it, and is his diagnosis based on the observations of one teacher, or more?
Do you have a current WISC or Woodcock Johnsnon Cognitive? If you do not have one of the other of these, I would do two things, I would first, call a neuropsycholgist and pay for a full evaluation and get a Woodcock Cognitive (they will know what this is, and probably use it) and two, I would write to the school distirct and ask for one, and revisit the evaluation they did, disagree with it, and request an independent evaluation, at the schools expense.
I can help you sort through these things. If you are holding an evaluation with these tests in it, go to www.wrightslaw.com and read "Understanding tests and measurements for Parents and Advocates" This will help you understand some of what the data means.
What you are describing might be something entierly different than PDD-NOS, and if they are only offering speech, I am highly suspicous of a school diagnostic finding autism. Can you send me more information so I can help you? Unless you are just the type of person who is in total denial (which I just don't get from you) then this is very questionable.
If you want me to help, let me know,
M.