It's definitely on!
Momoa recently attended the Indiana Comic-Con where a fan asked Momoa to write a response to how the DC haters can join the DC universe.
Check out the pic below.
Jason Momoa will be featured in Batman Vs. Superman, Justice League and his own standalone Aquaman movie.
"Batman v Superman: Dawn of Justice" has a March 25, 2016 release starring Ben Affleck as Batman, Henry Cavill as Superman, Gal Gadot as Wonder Woman, Amy Adams as Lois Lane, Laurence Fishburne as Perry White, Diane Lane as Martha Kent, Jeremy Irons as Alfred, Jesse Eisenberg as Lex Luthor, Ray Fisher as Cyborg with Callan Mulvey, Holly Hunter and Tao Okamoto in new character roles for the film. Justice League is to follow directed by Zack Snyder as well.