North, who happened to voice Superman for LEGO DC Super Heroes: Justice League - Attack of the Legion of Doom!, Lego DC Comics Super Heroes: Justice League vs. Bizarro League, Lego DC Comics: Batman Be-Leaguered and Superman vs. The Elite animated movies as well as voicing Superboy in the Young Justice series told GrantLand the mystery project is going to be big.
Lastly, he’ll visit Warner Bros. for a video game, another “big, big project” that he can’t talk about other than to say, “That’ll be another 10 years of my life.”
With Batman: Arkham Knight being the last of the Rocksteady Batman games, it's thought a Superman and/or Justice League video game may be following as WB Games is currently developing two DC video games, and what is thought to be Superman video game concept art has hit the net recently (see below).
A game designer also happened to post on his online LinkedIn resume that he is working on an upcoming Superman video game with GameOn Audio, the audio and motion capture company that worked on Batman: Arkham Origins.