How are you doing? How are you taking this news? I'd send you a big hug but it icon button isn't working!
My DD used to have the dx PDD-NOS, but her dx was changed to Asperger's when she was 13. My understanding of PDD-NOS is that it is the dx used when a child is on the autism spectrum, but doesn't neatly fit into a specific type of autism. Often kids with the label PDD-NOS are on the higher end of spectrum, but not always so. Because it is a catch all, dx, it can mean almost anything.
The full report should tell you a great deal more about what they are actually seeing right now.
Evals are sort of like photos. They are just a snap shot in time. Depending on what is going on with your child and how he changes over the years, he'll most likely have more eval. Just as a photo can't tell you what a child will look like in a year or two, or when they grow up, an eval and a dx can't tell you what they will be like. And that's a good thing. There's lots of hope.
My favorite book on the topic is "quirky kids" by Klass. It is about several related dx's -- including PDD-NOS. It's a great starting place. It talks about the kinds of professionals involved, options for therapies, issues with family life etc. It has a very friendly tone -- like having a good friend who's BTDT and can kinda show you the ropes.