I could see Batman doing a Fury-esque thing where he has studied the various heroes and meta-humans that have started popping up to determine who would be best to form a team to face some threat that he knows is coming.
Also, Martian Manhunter Film Noir movie, please. Do it on the down low, fairly low budget, no-name actors, don't even reveal the fact that its a Martian Manhunter movie until a post-credits tease. Just have the main character do seemingly weird stuff that, while you're watching the movie you don't really give a lot of thought to, but once you figure out he's the Martian Manhunter, you re-watch the movie and have a whole different understanding of what just happened and why the main character seems so distant and strange.
Post-credits tease is the detective we've been following enters his apartment. Takes off his hat, sits it down on a small table, then reaches up towards the light switch.... but pauses. He turns towards the shadows and says "You might as well come out now." and BAMN the dark silhouette of BATMAN appears, flowing forth seamlessly from the shadows. His gravely voice... "We need to talk." Cut back to the detective, we see him walking from the right side of the frame, to the left. "I suppose we do," he says. His shadow grows behind him, as he walks off-frame.... then shifts from the shadow of the detective to the shadow of the pointy-headed Martian Manhunter. End
Stealth release movie of the century. Make it happen, Warner Bros.