I think that Farkel's point is valid. People believe in crap because they WANT to believe in crap. I mean, there are still people who claim to be "samaritans" living in Palestine! Still practicing what is left of their millennia old religion - and they are dying off.
I really can't see another Rutherford, though - there just isn't anyone that charismatic in the organization! They've all been disfellowshipped or have sought better opportunities.
The status quo will continue - mediocre growth in developed lands, even declines, and continued growth in the Third World, because they really don't have anything else going on.
CZAR