I think the trend as seen most carefully by those who watch them closely (us)...is that they have peaked and are now on a decline.
Everything is against them:
1/ Apparent serious and long-term cash-flow crisis.
2/ The general decline in Christian belief in the West and a tendency towards a private, personal spirituality.
3/ Their loss of income from their historical source of revenue namely printing.
4/ The openness and transparency of internet information which easily exposes cultic behaviour especially to newly contacted people.
5/ Negative publicity regarding child abuse cases and their attempt to keep their name clean at the expense of, and with total indifference to the welfare for the abused.
6/ The total failure of their most cherished eighty year long hope in the arrival of Armageddon within the life- span of the generation who saw 1914.
7/ The attempt to explain away their failure of the 1914 generation doctrine with their ludicrous "overlapping generations".
8/ The increasing loss of faith in the decisions of the GB resulting in a reluctance to contribute financially or by deserting the organisation completely.
(Please add if you can think of other ideas or better ones).