You know how you're supposed to take certain news with a grain of salt? Well, consider pouring that salt shaker down your mouth before reading this: the National Enquirer (I know, I know) is reporting that Bill Murray was so unimpressed by the script for Ghostbusters III that he shredded it, stuffed it in a box, and sent it to Harold Ramis and Dan Aykroyd with a note reading:
No one wants to see fat, old men chasing ghosts!
Now, before we start jumping on the National Enquirer, let's acknowledge that despite the fact that they are indeed a tabloid, they've also done some good reporting over the past few years, including being the first to jump out with the John Edwards affair in the 2008 presidential campaign when no other paper thought it was solid enough to report. This is obviously a straight-up entertainment story, so it can't be put on the same pedestal, but honestly: can't you see Bill Murray doing this? It sounds like the kind of thing that he'd do; he's famously difficult to get a hold of when it comes to scripts (and reportedly didn't even read the original Ghostbusters script until he showed up for the first day of filming), and has had a love-hate relationship with Ghostbusters 3 since rumors started floating around about it in the middle of the last decade.
Screenrant has done a lot of good stories on the continuing saga of Ghostbusters 3, most of which are linked to from this newest post, but to recap: Murray is reportedly somewhat taken aback by the fact that the script for the third installment in the franchise is being written by Lee Eisenberg and Gene Stupnitsky instead of Ramis and Aykroyd, who of course wrote the first two installments of the film. Eisenberg/Stupnitsky don't have much of a track record, having been behind the bomb that was Year One and the success that was Bad Teacher. Murray has never really committed even to the idea of a Ghostbusters 3, with the closest sign that he was going to do it perhaps having been his appearance last year at the Spike TV Scream Awards in full Ghostbusters livery.
Again, this is all kinda-sorta hearsay at this point. Apparently Murray, Aykroyd, Ramis, Sigourney Weaver, and Sony all have equal stakes in the creation of a new movie, so they all have to sign off on its creation before it can go forward, even if Murray doesn't even want to be in it. If the stuff above is true, that might never happen.