There's a rumor that part of that script started off to be a part of Ghostbusters that Dan Akroyd wanted to use; but until Bill gives up his rights to the GB franchise, the movie won't be made. Bill Murray doesn't want to do that movie at all for some reason. My sister saw Bill in an Ice Cream shop a few months ago and I had her ask him about GB3, and he said "heh....no". Anyway, the early script made by Dan had him and Egon hiring 4 new, young Ghostbusters (possibly their children, including Bill's Oscar), and setting them up with all new equiptment to carry on the ghost busting business. While this is happening, Hell becomes full, and starts sending the overflow of souls into Manhattan. Stantz decides that the only way to deal with this is to transport themselves to hell with the other Ghostbusters, and ask the devil why he's doing this. The devil will be the form of a sleezy lawyer type...(shock!). Anyway, that's the basis of Dan's early script, but as of now, there is no signs of a GB 3. When there is, I'll be the first to tell you =)