The thing is, our generation wasn't "brought up" on any particular OS. For the last 20+ years, the kids understand technology better than the parents. When our generation has kids, they'll have parents who understand technology. That should be interesting...
I think we'll see very similar behaviors. When I talk about understanding technology, I understand that there are consistent paradigms of operation and expected outcome surrounding technology. A generation is long enough for a paradigm shift, meaning that there will be newer, more advanced ways of interacting with technology by the time our generation has kids.
I think we can already see evidence of this. While I still prefer to use the DOS command line to perform particular operations, and I think most of us prefer to not use voice-control software to use the computer, these things will change as the paradigm shifts. Particularly for people who begin using the computer at a time when voice command is not so imprecise (I know this is an aim of Vista; whether it will happen, though, I am dubious), they'll likely tend to use it much more frequently because they won't be as frustrated with it as we have been.