The whole heroes aging, having families and children, and train new generations of heroes
were big in the Justice Society of America part of things.
Which, of course, didn't really survive into the new52.
At least so far. I'm still hoping they can find a way to get the JSA new52ified.
(And if not, put them on a parallel earth were heroes were around longer
so that I can actually read comics about my favorite heroes and their legacies)
I can say one thing though, even if it's a bit off topic:
while the new52 may be a good way to get into the DC universe at the moment,
many of the older fans have a harder time to get into it.
Especially considering some of the more drastic changes some well established characters have undergone.
That said, I like what they're doing in Earth2 (and by extension in Worlds' Finest).
Those two may actually be my two most favoritest of the new52.