Variety reports that the new target release date for the project is May 16, 2014.
Sources say "Turtles" was pushed because the filmmakers and studio felt they wouldn't be ready for the October shoot date. Paramount had no comment.
The shutdown is not indefinite and the plan is to work on the script over the next couple of weeks in order to beef up the material and bring the budget down slightly.It sounds like there are concerns about the script in its current state, but they're not starting over from scratch, so it's unknown if the "alien" element of the story will remain or not. But if they're trying to bring the budget down, it may be that they need to tone down the amount of effects-heavy space elements. It will certainly be interesting to see how this develops!