I'm 38. Personally I think there will be a new generation of model railroaders coming along since trains are once again playing a more prominent role in American life, both in carrying cargo and people. Model railroading appeared when trains were *the* way to get place to place: people primarily modeled what was then the current day, and this wasn't solely a "nostalgia" hobby.
I don't have kids, but I do a lot of "train ambassador" duty to my friends' kids and nephews, and I have at least one friend who is getting into trains as a father & son activity. I see lots of parents about my age with kids at the railroad museum, and it's hard to tell who is having the better time.
Sure, kids are into high-tech gadgets, but when were kids not into high-tech gadgets? It all depends on what is high-tech when you're a kid: A crystal radio set? A cellular phone? A spiffy Lionel electric train? A spiffy Atlas RTR DCC locomotive with working lights and sound? Sure, the kid with the cell phone doesn't learn as much about how to build things as the kid who built his own crystal radio set, but there are lots of things you can do with the cell phone that simply weren't possible in crystal radio set days.
Model railroads ARE high-tech gadgets, and always have been. Model railroading has survived the coming of slot cars, the waning of trains from American life, and the passing of several generations. As long as there are trains, there will be toy trains, model railroads, and young kids of all ages who want to play with them.