The first (of 3 and counting!) re-definition of "generation" in 1995 had a subtle, yet definite, effect on JW morale. That definition disconnected Armageddon from people alive in 1914, thus apparently pushing back Armageddon several years.
Since that time, the rate of baptisms has pretty steadly declined. The overall numbers keep going up, but the slope of the curve has changed.
Over the past couple of years, with a constant drumbeat of the "imminence" of Armageddon, they seemed to get a bit of their mojo back. After years of 1 or 2 % increases in the US, it's been 3 or 4 % recently. In Europe, after years of 0% or even "negative growth", rates inched up to + 1 or 2 %.
But now they come out with another article which, as I demonstrated above, clearly pushes back Armageddon even further - perhaps even decades.
What will be the effect of this article, once JWs absorb it?
I'd say, short term, not much. But as years pass, including the "100th anniversary of Christ's kingship" in 2014, I expect there will be an even more pronounced drain on morale.
By 2015 we might begin to see across-the-board negative numbers in JW year-over-year numbers (undoubtedly, to be soon followed by the cessation of publishing the reports).