Apparently the title change was confirmed during Paramount's CinemaCon presentation, when they debuted the official logo for the film, which clearly read 'Teenage Mutant Ninja Turtles'. Now, if only they've dropped the whole alien origin thing...
The controversial TMNT reboot is being produced by Michael Bay (Transformers), with Jonathan Leibesman (Wrath of the Titans) directing from a script that has most recently been rewritten by Evan Daugherty (Snow White and the Huntsman). Filming is now underway with a cast that includes Alan Ritchson (The Hunger Games: Catching Fire) as Raphael, Pete Ploszek (Parks and Recreation) as Leonardo, Jeremy Howard (How the Grinch Stole Christmas) as Donatello, Noel Fisher (Battle Los Angeles) as Michaelangelo, Megan Fox (Transformers) as April O'Neil, Danny Woodburn (Seinfeld) as Splinter, and Will Arnett (Arrested Development) in an as-yet-unspecified role.
Ninja Turtles is set for release on June 6th, 2014.