Injustice 2 beta - sign up
The closed beta will be for Xbox One and PS4 - you can sign up here: https://beta.injustice.com/
No word yet on when the beta will be active, how many slots are available, or what characters or features will be active.
I will update this article when more information is announced.
So far, the developers have said 2 will include a longer, more involved story mode, randomized loot system that lets you equip items to change stats & abilities, and a larger roster than the first game; confirmed characters include Aquaman, Atrocitus, Bane, Batman, Brainiac, Blue Beetle, Darkseid, Deadshot, Flash, Gorilla Grodd, Green Lantern, Harley Quinn, Poison Ivy, Robin, Supergirl, Superman and Wonder Woman.
Additionally, certain characters can equip "premiere skins" that change their look, voices and effects. For instance, Green Lantern can be either Hal Jordan or John Stewart, Supergirl can become Power Girl, and Flash can become Reverse-Flash.
Injustice 2 is scheduled for release on May 16, 2017.