The plan is to have not just Batman and Superman in the film but several members of the Justice League as well. It’s unclear which members, but Wonder Woman (Diana Prince) and the Flash are said to be locks to make an appearance in some fashion, whether that’s a significant role or a cameo.”
DC is introducing more and more members of the Justice League into their cinematic universe. There is also a planned CW Flash TV series in the works–a spin-off from Arrow. There’s no word yet on whether the film and TV series will be connected. If they are linked, that could also bring the Green Arrow and Black Canary from Arrow into the mix. If this is the case, we could have six members of the Justice League pre-established for a Justice League movie. Despite the earlier plan of introducing the team of heroes all together in the Justice League movie, it seems DC is taking an idea from Marvel and creating a roster of heroes in advance. The presence of multiple heroes lends some support to an earlier rumor that the film may be inspired by the popular comic story “Kingdom Come”.