Why would you want your own biases get in the way of educating your son? Python is a great first language because it is both approachable and practical. You can go in any direction... webapps, scientific computing, and even games (as I've already suggested).

I learned QBasic when I was 9, when I was 11 and realized the world wasn't developing real applications in QBasic, I was pretty upset and never wrote a line of QBasic ever again. I was pretty bummed at the time, and moved on to C.

There certainly is a reason top universities are moving to Python to teach beginners programming...