Based on the various stops-and-starts surrounding the fabled third installment of the Ghostbusters franchise, it's best to take the following with a ghastly grain of salt -- but according to some sources, the movie could begin production as early as next spring.
Production Weekly reports that they're "hearing that Sony Pictures is planning to put Ivan Reitman's Ghostbusters 3 into production in May 2011." Last we heard, the third Ghostbusters film's screenplay was in Dan Aykroyd's hands; but with round after round of criticism from Bill Murray's corner, one has to wonder how realistic Ghostbusters 3 is, or, at the very least, whether or not Murray is going to play ball in any sort of meaningful way.
But, for whatever it's worth, it appears that the film may be on track for a production start in May of next year. If that's the case, we're bound to hear about casting and other official news soon. But based on how this project has progressed thus far, I wouldn't hold my breath.