Michael Bay's response:
"Fans need to take a breath, and chill. They have not read the script. Our team is working closely with one of the original creators of Ninja Turtles to help expand and give a more complex back story. Relax, we are including everything that made you become fans in the first place. We are just building a richer world."
If they are still aliens I don't care if you did pay off and collaborate with Peter Laird(Eastman has been bought out remember). The movie still wouldn't be about the TMNT.
It's like having a movie where Bruce Wayne's parents are alive and well. But, hey take a deep breath it's still going to be great...trust me, we worked with the Bob Kane estate on some details.