I think that over time, the org will drift even further outside of the mainstream, due to both the marginalization of extreme religious zeal in general in the Western world, as well as the developments within that have already been mentioned here. Some will never leave and some will continue to join due to things like prestige within the org, being part of a special club that thinks it has all of the secret answers, etc.
It's certainly looking possible that the org might follow a similar track as Scientology. That organization has definitely realized an increasingly stigmatized status recently. Not that LRH was a normal guy, but the newer leadership is evidently a new breed of crazy, who has ruled with such an iron fist that a lot of higher-ups in that organization who seem more reasonable have left. 15 years ago, when celebrities joined the Church, it would raise an eyebrow or two but probably not hurt their careers. Today an actor who joins Scientology would be taking a major career risk, and overall membership numbers have dropped significantly. That hasn't really happened yet within the WTS, but in light of recent developments, it's possible they're on the same curve, just a little behind.