What would probably happen is the conventionalization (a new word?) of the religion to a more user frindly org. (the only ones that can survive in Western Society at least. The org. was really agressive and confrontational in earlier decades (placards, cars with loudspeakers, etc...) compared with today's kinder, gentler version when dealing with outsiders.
Voluntary service, more holidays, less career restraints, etc...
I don't think an apocalyptic religion can survive without its apocalypse! This conventionalisation process will continue unitl JW's are more like your average American bible belt morons.There will always be people who'd rather be told what to do than think for themselves -Hey- that's what religions are for anyway!