There are new people appearing on this and other boards on a daily basis. Its damn close to a mass exodus at this point. But I agree, it will never fully go away. Further splinter, almost for sure. It already is. The New Order Mormons already are basically a splinter group that meet in the same building.
It depends on your definition of destroy. If you mean forcing enough change on the morg that they are not cultish and fit into society then it's a maybe. If you mean utter destruction and diappearance? That last one is unlikely.
going to stick around. The LDS Church; the businesses, corporations, land ownership, etc. will change but I don't think it will ever be destroyed -- as in non existent.