A TMNT fan has gotten their hands on Michael Bay's Ninja Turtles' script.
Source: The TANT Script: Reviewed
To start off, the Shredder was going to be in the movie, but he's called Colonel Schrader and is a part of a secret military operation known as the Foot. Casey Jones would have been the focal point of the movie (the author, even compares how eerily similar Casey is to Sam Witwicky from Bay's Transformers franchise even down to the same sort of lady troubles involving April O'Neil who'll be an intern at CBS.
As for the Turtles themselves and their first introduction to Casey and April, it goes something like this:
Then we get to see how the Turtles get their multi-colored bandanas, which is classic Bay:
Now, I know what you're thinking: "take this with a grain of salt, right?" Maybe. Another fellow TMNT fan decided to show the review to TMNT co-creator Peter Laird in hopes of a comment and confirmation it's real. Laird stated:
Someone else alerted me to the existence of this script, and I just a few minutes ago finished reading it. If it is, in fact, the actual draft that was rejected and caused the production of the next TMNT movie to be pushed back to 2014 because the script was unsatisfactory, then I think all true TMNT fans should be grateful to the new "powers that be" that they did not allow this wretched thing to go any further. It could definitely be taken as a good sign if that is the case.
It reminds me of one of the reasons I am glad to not own the property anymore... because I don't have to tear what little hair I have left out while trying to fix junk like this. -- PL
If you're a glutton for punishment, the blogger has even more script passages posted on his review. Be warned, though; it isn't for the feint of heart.