When Disney acquired LucasArts, the company stated that "all projects are business as usual." That seemed to indicate Star Wars 1313 was still on-track, but sources state that the game has been put on hold.
Three separate sources reportedly told Kotaku that game development has been stalled since November. It had been slated for a release in late 2013, but the lapse in development time may push it into 2014. LucasArts, for its part, claims that the game is not canceled, but noted it the company is "working diligently to take advantage of the tremendous opportunities that the new Star Wars movies present." This gels with the sources' claim that the gaming division's focus has been put on the upcoming Episode VII, rather than side-stories.
The sources went on to state that the game had originally been conceived in 2009, as a tie-in to the planned live-action television show. It had been called "Underworld" at the time, and was meant to be a much darker tone than usual for Star Wars. Further, it was planned as an open-world RPG with episodic downloadable content. The game was then reportedly scaled back and rewritten in 2010 once the show was shuttered. The story was apparently still being developed, with encouraging words from George Lucas himself, when it was shown at E3 2012.
We have contacted LucasArts for comment, and will update if we get a response.