The articles I've seen have implied that Jason Todd is rumored to appear, and with the easter eggs they've been dropping it looks like a possibility. Along with Ra's al Ghul, which suggests from details emerging that they will base or at least be influenced by the resurrection of Jason Todd and the Red Hood story. In the animated version, Ra's stole the dead body and placed Jason in the Lazarus Pit, unfortunately, due to the amount of time he had been dead and such it drove Jason insane. Dawn of Justice seems to follow more along the lines of the animated Justice League: War. And influenced by the New 52 universe DC established. The writers like to borrow story elements from various stories/parallel earths. They've stated they cherrypick stuff to create something new. So, its possible they picked Batman's darker attitude from The Dark Knight Returns and method of operating. Geoff Johns is now Co-President in charge of DC Entertainment.
Then, by the time the solo Batman movie comes out, The Joker would be an old man if they are using the stories from Alan Moore stories. The villains in The Dark Knight Returns was primarily The Joker who feigned being cured to lure Batman into a trap and then framed him for his murder. The Government sent Superman to kill Batman. The overall villain established by Moore in the graphic novel was The Government.
Agents of S.H.I.E.L.D. would've been cancelled long ago as they had steady drops in ratings, yet they were saved each year. Agent Carter didn't have the special effects like Agents of S.H.I.E.L.D. with the inclusion of the Inhumans and upcoming superpowers. Agent Carter still had a decent following. And, Longmire isn't the only show to have been saved by Netflix or rebooted on Netflix (Voltron). The logic doesn't gel. They had a perfectly good show with a strong female lead character, and they axed it. The same thing is happening with Jessica Jones. The new season won't start till next year. Why? They wanted to make way for the new shows, Iron Fist, The Defenders and Luke Cage. I agree, Agent Carter had a lot of wasted opportunities with establishing S.H.I.E.L.D., meeting characters like a young Hank Pym. Ant-Man showed the Triskeleon (sp?) being built in 1989 with a brief cameo from Peggy Carter. Netflix could have saved the show if they wanted to, but Disney/Marvel execs probably said no.