Sadly (or maybe gladly), it's being widely reported today that Sony has failed to greenlight this troubled franchise sequel. The studio won't make a final decision on whether or not they will move forward until this spring, which would push shooting out of the summer and into the late fall for a projected 2014 release.
Ivan Reitman is still attached to direct from a screenplay by Etan Cohen, with Dan Aykroyd, Harold Ramis, and Sigourney Weaver all reprising their roles from the first two movies. We also reported in August that Bill Murray has dropped out for good (but, hey, that could change, because it has in the past).
The story will reportedly revolve around a new team of Ghostbusters who are taught the trade by the returning cast members.