I'm a huge fan of the notion of Superman and Batman and the rest of the Justice League being the second generation of superheroes in the DCU, with the JSA being the first. I understand that some people don't jive with that because they like the notion of Superman and Batman being the first two superheroes in the DCU just like they were the first two superheroes (in the modern sense) in real life. I get that, and I do kind of feel that way to, which is why I'm a huge fan of the compromise Geoff Johns came up with in the JSA episode of Smallville, where the JSA was a secret society that did it's crime fighting and world saving from the shadows, so Superman and Batman are still the first public superheroes who knowingly and willingly made an impact on the wider culture.
As such, I'd love to see some embers of the JSA show up. Maybe bring in Ted Grant and Wesley Dodds as the guys who taught Bruce how to fight and solve crimes, respectively. Have them present themselves as a retired boxer/Marine and an old eccentric criminology enthusiast, but hint at their secret double lives that Bruce seeks to emulate, albeit in more of a "loud kind of quiet" approach.