I see several possible scenarios.
1) As noted above, the increased exposure could cause other victims to come forward. It might also prompt other men in responsibility to show some courage and add their voices to that of Bill Bowen. (If I were still an elder, I would like to think I would have done that. At this point my voice means next to nothing.)If a chain reaction could be started, the WT could find itself under great pressure to change its policies and create a more open, democratic atmospere. I don't think even this best-case scenario will lead to the down fall of the WT. But the WT would probably look so different from what it does today that it would be almost as though it had been toppled.
2)A combination of luck and stealhy moves by the WT might enable it remain largely intact. If the coverage gets swallowed up by the scandal involving the Catholic Church, it all may blow over rather quickly. It will still be a lot of sweating for the WT, but they'll be able to make changes that are less drastic. This is still good for those who are trying to help people who feel trapped by the WT. I think that the more the WT opens up, the more they will feel pressured keep making changes. In the long run, #2 may have the same result as #1, but it'll just take longer.
3)The Dateline episode may only turn out to be about as scandalous as the UN business. It would be terribly damning and very disturbing to those in the know, except that JWs won't be in the know. In this scenario at least the info will be available for those who feel something isn't right about the "truth" and start to investigate. This wouldn't be the great coup everyone is hoping for, but it would add a little more fuel to the fire.
4) Might the Jws feel attacked and therefore compelled to withdraw even further into their fantasy world? This has happened in the past. The scandals have caused people to leave, but those who stay feel even more committed that before, which eventually leads to more preaching and more growth. I don't see this as very likely. The difference this time, I hope, is that the scandal will become and remain a part of the public record, which will mean that it'll be harder to deny than 1975, for example.
5)Maybe this is the begining of the great tribulation. The gov'ts are turning on false religion and then they turn on the WT and boom, we're all toast. Whaddya think?!? (I consider this the least likely outcome, right there with UFOs and JFK conspiacies.)