My daughter was diagnosed with PDD-NOS a year ago and turns 3 in January. She's adopted, so I don't know if her birth parents were "smart" or "geeky" but I can second everything else here. My wife and I are smart and geeky, respectively.
After talking with a lot of doctors and specialists over the past year, my feeling is not so much that the incidence of ASD is higher as much as it is that we're identifying it better now. But there are two things I know for sure: that early, intensive intervention is extremely important and that dealing with this disorder is just fucking heartbreaking. Our daughter is at the "mild" end of the spectrum, and we are very fortunate that we're able to afford the speech, occupational, and physical therapy as well as the many specialists who have been involved over the past year. My insurance through work is adequate for regular stuff, but totally sucks for getting treatment for Autism. As a result, we're out-of-pocket to the tune of tens of thousands of dollars just for the past 12 months and it's not looking like that's going to change. All we can do is advocate for her and make sure we exhaust every possible legitimate avenue for treatment and hope we can pull her far enough out of the hole she's in to make a difference.
Still, I can't stress strongly enough that early diagnosis and intervention is the best way to mitigate the effects of Autism. A lot of parents don't want to admit that there could be anything wrong with their child, which just makes things worse for everybody. We all want to think that our kids are perfect and all, but denying that there is a problem leads to bad decisions, lack of care, and much worse outcomes.
So good luck, anonymous dude. Make sure your kid gets a good IEP and starts in the school system at age 3. And keep up the work on all the therapies. Try to get as much ABA therapy as you can afford and stay away from the snake oil "amazing cure" crap. Like you, I have no idea what the future holds but I'm determined to do everything I can to help my daughter be happy and healthy.