Jw's aren't the only apocalyptic religion, there are many. They are all looking for Jesus to return - how he does it varies a little . Most know the book of Revelation and I hear a lot of folks quoting it. Jw's are just one of MANY end time religions . Also, even if people won't tell you to your face they think the world could end, a lot non-religious people think so too.
It seems in our literature , TV, and music we are hell bent for this world to come to an end. Think about all the movies, " Escape from New York "(one of my personal favs),, and many years ago Soylet Green ( 1973) and well, we can all name a lot of end of world movies including the current vampire and zombie end of world craze.( TV series The walking Dead)
If jws stay alive they will just keep reinventing themselves. Seriously, if Mormons,Scientology, and numerous other wacko religions can survive, why couldn't jws? It will become a lifestyle religion , much as the Mormons are.
The next time a jws tells me the Wts is still here b/c God's spirit is behind it, I plan on asking if God's spirit is backing the Catholic, Baptist and all those Eastern religions.