Because of the Internet and general osmosis, I think that JW's will overtime become just another mainstream religion that nobody notices.
It can be done. It takes authority with a new sense of purpose. Leadership.
Mormons are a good example of this. If you look at their origins, battles, weirdness and transformation over time you can see what is possible.
The Worldwide Church of God is another example.
Mainstream Christianity can handle End Times nonsense as long as it is kept inside a bubble of fictionalized speculation such as Tim LaHaye's LEFT BEHIND series or HAL LINDSEY'S ministry. Admittedly, Lindsey is on the fringe of the evangelicals, but he isn't considered apostate as such.
Where the Jehovah's Witnesses are stuck and cannot move forward is in confronting the violent rhetoric of Judge Rutherford and the nasty tone
of the era which made JW martyrs.
The truly "successful" ministers right now are SELF-IMPROVEMENT pastors who make christianity about YOU and not God, per se.
Joyce Meyers, Beth Moore, Joel Osteen, Rick Warren make you feel good about your life and your future. God is your constant pal and is rooting for you.
The death and destruction scenarios are kept way back in the murky shadows.
Let's face it, Jehovah's Witnesses achieve a lot of self-importance from condemnation of others. It would be a radical about face to suddenly become
nicey nice.