During the Comic Con panel, Snyder says he wanted to take visual cues and elements from TDKR(eturns), but the story itself wasn't based on any particular source material. "Original story" from Chris Terrio he says and from something I read awhile back, Goyer was not really part of this project, but they're giving him a producing credit and possibly a writers credit as well.
The reach with the Joker story would be kinda lame. Also, it would take away from a future Nightwing appearance and/or a Jason Todd/ Red Hood storyline.
If the theory does prove to be true though( which is pretty doubtful), the fact that Leto is actually a year older than Affleck in real life is crazy, dude has some great genes Edited by Jiffyl00b - 7/15/15 at 2:57pm