It’s not set in stone, but here’s the newest posted cast for Justice League of America from FilmDrunk:
Superman - D.J. Cotrona
Batman - Armie Hammer
Wally West/The Flash - Anton Yelchin
Aquaman - Santiago Cabrera
Iris - Zoe Kazan
Wonder Woman - Megan Gale
Talia al Ghul - Teresa Palmer
Green Lantern – Common
I was feeling bad about not knowing who any of those actors are except Common (um, as a sing-er), but then I actually read the post and looked at the photo accompanying. 
Mmmm… is there ven a script yet???
I would have to agree… I have heard of Common but you are more popular around THIS house.
I have no idea who Common is. But I’m glad they’re all no-names, because that means it’s more likely to revolve around a strong script instead of one well-known actor.
D*o*gDawg, the movie isn’t set to be released until 2010-ish so I’m guessing the script only partially exists at best.Maman, awwwwwwwwww.
Thank you!!!!!! 
Avi, such an excellent point. Some of my favorite movies are with people I don’t know.