We know Megan Fox will play as April, now we apparently know who will play as one of the turtles! According to Deadline, Alan Ritchson (The Hunger Games: Catching Fire & Smallville) will be the most aggressive turtle, Raphael. He won't be strolling around in a suit like the classic films, though. The film directed by Jonathan Liebesman will have CGI turtles. This mean the actors will do performance capture, like Andy Serkis as Gollum/Caeser, or most of the cast in Avatar.
Ninja Turtles is slated to come out June 6, 2014. Here's the plot summary on the IMDB page (I'm aware those aren't always 100%, but it beats a leaked script that everyone says is long gone, yes?):
Aliens invade Earth and inadvertently spawn a quartet of mutated reptile warriors, the Ninja Turtles, who rise up against them to defend the world.