Potential spoilers follow for Justice League.
According to someone who works in the VFX department of a company working on the WB movies - who recently offered a description of the Green Lantern costume - he/she also worked on a scene involving Henry Cavill as Superman.
According to the leaker, Superman flies down in front of the Kent Farm and punches something big. It's said the object is unknown because it was done using green boxes with motion-capture markers, so the leaker doesn't know what Superman actually punched, but it's said to be something really big (the green boxes are used for CGI purposes and get replaced digitally in post-production).
We can speculate it may be a Parademon that goes to the Kent Farm possibly looking for Clark Kent or Superman, which means Steppenwolf knows all about the Justice League members and possibly their real identities (assuming our guess is correct).
The leaker also adds that he/she hasn't seen any footage of Superman in the black suit or with a beard, but the footage he/she has seen has been with the red and blue Superman costume.
Obviously this is a rumor, so take it with a grain of salt (via reddit).
Justice League has a November 17, 2017 release directed by Zack Snyder, with the story by Chris Terrio and Zack Snyder, the screenplay by Chris Terrio and Joss Whedon, and stars Ben Affleck as Batman, Henry Cavill as Superman, Gal Gadot as Wonder Woman, Jason Momoa as Aquaman, Ezra Miller as The Flash, Ray Fisher as Cyborg, J.K. Simmons as Commissioner Gordon and Willem Dafoe an Atlantean, Nuidis Vulko.
Fueled by his restored faith in humanity and inspired by Superman’s selfless act, Bruce Wayne enlists the help of his newfound ally, Diana Prince, to face an even greater enemy. Together, Batman and Wonder Woman work quickly to find and recruit a team of metahumans to stand against this newly awakened threat. But despite the formation of this unprecedented league of heroes—Batman, Wonder Woman, Aquaman, Cyborg and The Flash—it may already be too late to save the planet from an assault of catastrophic proportions.