Back in October, the Star Wars world was rocked when it was announced that screenwriter Michael Arndt (Toy Story 3) would be leaving Star Wars Episode VII, and would be replaced by the film’s director J.J. Abrams and producer Lawrence Kasdan.

But Abrams states that the reason he had to take over the screenwriting duties had nothing to do with some insidious conspiracy, but more to do with the scheduling.

This also to do with Disney announcing that the sequel will be out in December 18, 2015. Which such a tight deadline, Arndt had no choice but to pull out:
It became clear that given the time frame and given the process and the way the thing was going that working with Larry in this way was going to get us where we need to be and when we needed to be. Working with Larry Kasdan, especially on a Star Wars movie is kind of unbeatable. ...

    Working with Michael was a wonderful experience and I couldn’t be a bigger fan of his or adore him more, He’s a wonderful guy and was incredibly helpful in the process. [This event] doesn’t preclude working with Michael again in the future, he is one of the best writers around.
Of course, the biggest problem remains: Would Abrams be able to finish this movie in time and still make it good? Guess we'll just have to cross our fingers and wait until 2015 to find out.