The JWs will follow the pattern of small towns and localities throughout Australia (if not the world)
In the 1940s our little towns were full of life, few had cars and most rode a horse. Hell the farmers in my district did not transition from draft horse to tractor till into the 1960s
By the 1980s these little towns of 100 people were all but gone save for a pub and a store and ten years on most of that had gone as well. A drive through country australia reveals a host of ghost towns, populated by 10 people and no hotels or shops...they all got boarded up years ago as cars made travelling further faster the norm. Nobody needed to stay in these little places, there was no work, the farmers couldnt afford to employ them and so the towns died.
I feel its a pretty good analogy of religion too.
Our local town lost its minister last year and the church didn't replace him...the country is full of churches that are now homes as the only attendees in the towns are oldies who have been 'faithful' since they were born. Their children were less inclined and the grandchildren have no godly interest at all. The manse is rented out now and the church sees a travelling minister once a month.
Jehovah's Witnesses will go the same way in country australia. One day, vibrant congs in towns of 10,000 or less will be nothing more than a familiy or two of old originals or those who bought a cheap house in a dead town and can't move out. The kids will have gone to the city and got busy trying to make living and the grandkids will bail the religion at 14.
One day, the run down kingdom hall that was built by the locals long before quickbuilds and loans from the society were the norm will be host to a visiting speaker once or twice a month and the rest of the time the 'congregation' will be kept together by a handfull of old sisters valiantly following the watchtower study and going door to door for a couple of hours.
The ethnic congregations, although in larger cities are essentially, a small town in themselves. There may be only a few thousand of whatever ethnic group surrounded by tens of thousands of regular australians (if there is such a thing now) Even these ethnic groups will slowly die as its only the oldies that still dont speak english keeping them going. All the 'clubs' for ethnic groups have opened their doors to anyone for a dollar because they know if they dont change the 'club' will be gone in just a few years.
The difference is that the JWs wont change for a million dollars and there lays their demise.
Oz (sorry for the log post...i got all literary for a while)