Re: Language delay picked up by school psyche, now what?
I think people just couldn't think of anything to say.
Language delays aren't always autism, of course; but your little guy seems to have a bit of social-skill delay as well. And the test he took shows a profile that's quite characteristic of high-functioning autism. So your concerns are valid, and worth checking out, in my opinion. Moms are always most in tune with the kids, anyway.
He's already getting speech therapy: Good. In my opinion, the biggest obstacle that faces autistic kids is learning to communicate somehow; because once that's done, they can learn everything else they are lagging behind on: Social skills, stress tolerance, emotional tolerance, sensory integration. It's easier to learn when you have help, though obviously autistic kids, like any kids, can and do learn on their own as they grow.
Speech therapy is great; but if the problem is autism, there are other things your son will need to be taught (see above). You are already doing great by helping him maintain a friendship with another child; that is something I did not have as a child, and would have benefited from. (Also, the benefit to the other child is just as great: He will see your son as different, but will know him to be somebody who's OK to hang out with, anyway--a life-long lesson some people never learn.)
If your son has autism, it's probably mild. Even in these days of new knowledge, high-functioning autism sometimes doesn't get picked up until the pre-teen years, especially if the speech delay isn't pronounced. (We Aspies have a harder time of it--we often don't get a diagnosis until high school! A lack of speech delay, combined with intense special interests and social clumsiness, may be seen as "geekiness" instead of Asperger Syndrome--as it was with me.)
By the way, if this is scary to you, remember: Autism is a spectrum; it ranges from profound to near-normal. Your son is on the mild end; he'll be fine. Like I said, I'm an Aspie, and I'm pretty happy and doing what I want despite my disability. He just needs to be taught what's harder for him to learn than other kids. The thing he needs most, he's already got--a mom who loves him.