So the rejected script leaked. It's awful. Like, really awful. I'm looking for a download, but here's some tidbits:
•They aren't really aliens, they're "interdimensional beings" – Yes, Crystal Skull style.
•This does not stop them from insisting that they mutated due to a chemical spill anyways. Confusing much?
•The dimension they're from? Dimension X (Yes, Krang's dimension.)
•They're the "chosen ones" of their interdimension alien turtle race
•Casey Jones is the Sam Witwicky of the movie. He and April are 18-year-old high school sweethearts that graduate and move to New York when she gets an internship at CBS. He is an amateur hockey player, but takes up a job as a security guard at a furniture factory.
•He is the one that insists that they wear different colored bandanas because they all look the same to him after he discovers them while working.
•Shredder is not in the movie. Oh wait, yes he is... kinda. Fear Colonel Schrader (welp.), leader of the Foot Clan.
•Bebop and Rocksteady ARE in the movie and are described as faithul adaptations. Ditto for Krang, though he only has two lines of dialogue.
As for dialogue, here's some excerpts:
Raphael: "Kung fu? What do we look like, cartoon panda bears? We're trained in Ninjitsu. And we don't just
know it, we serve it for dinner..."
Raphael: "That damn frog was right. It
ain't easy being green."
*end of movie*
"You're never as alone as you think you are."
(cue Linkin Park... Okay, kidding, but might as well expect it)
Comicbookmovie has a full rundown of the entire plot...
http://www.comicbookmovie.com/fansit.../news/?a=66234
For those questioning, the original blog post that featured all the details was taken down due to a cease and desist letter that the author posted already.