Posted By:
barrysloateLeslie- first let me say I am double your age, but hopefully my opinion holds some weight. 
It's very hard to predict a generation into the future, but we can try. It's true that today's children do not collect current baseball cards as much as baby boomers did, nor do they play as much baseball themselves (my nephew plays basketball and soccer constantly, but never plays baseball). However, collecting artifacts is a whole different discipline.
I think there will always be an interest in vintage baseball cards, the same way there will always be interest in antiques. There is something intrinsically beautiful in an old object, no matter what it is (okay, maybe not an old rusty can opener, but you get my drift).
I wouldn't worry about the hobby long term. There will be peaks and valleys but I think old and rare memorabilia will always be avidly collected.