The mob - make it more intimidating
In "Begins" we were told how dangerous and powerful Carmine Falcone is. But it was never shown. Batman caught him at their first confrontation - that was all. Not intimidating at all like the powerful "Roman" in the comics.
The same with Sal Maroni in TDK. We never got the feeling that he runs Gotham's underworld.
So if they bring back the mob in the reboot - make it more powerful. Much more powerful. It's the mob and not a random street gang. It has run Gotham's underworld for decades. Maybe force the writers to watch movies like "The Godfather" trilogy or "The Untouchables".
The mob in the Nolanverse was a joke. No surprise that it was brought down by a single "Dent Act".