Well, if we're really going to be broad and open this thing up with an eye towards solutions, I'd like to throw my two-cents in and hope that his thread isn't so politically correct as to reject off-hand what I'm about to offer.
As for what spirituality might look like in 100yrs, that is hard to tell, but one thing that is certain is that it will be closely connected with the difficulty of life for whichever group of people is in question. Studies of religion among Native Americans have revealed that those with relatively "easy" lives (meaning abundant food, water and shelter) had fairly well-developed pantheons with different types of deities, etc. On the otherhand, other peoples lived under harsh conditions and barely survived; these latter groups had virtually no formal religion and even no marriage or funeral ceremonies.
This can be seen in contemporary situations as well: trendy, upscale American Buddhism is very philosophical and seems to completely lack the ancestor worship of its Eastern practioners where they are considerably poorer; new age thought and Wikken ideas are the animisms of Western affluents, and they are quite different from their counter parts in Central America/Carribean which involve ritual sacrifice and "magic"; and flashy, mega-church, Prayer-of-Jabez toting American evangelicalism contrasts with "low-brow" charismatic Christianity that is popular in developing countries.
So if we seek a solution to our broader problem in the form of spirituality, which I agree is the solution, we have to look at the root or core ideas of any spiritual system (because that system will be manifest in culturally-dependent ways--as I tried to indicate above).
For me, despite the black marks on its history, I think the core idea of Christianity is the way to go. That core is forgiveness--unconditional forgiveness with no strings attached. (I'm not saying that other religions don't have a concept of forgiveness, only that I think the notion of forgiveness is more paramount in Christianity.)
As a Christian, the solution to me is that we must forgive each other for being selfish--including ourselves. We have been selfish toward the planet, too--but it's only been recently that we've known the true depths of our selfhishness and how it has scarred the environment.
The giving and recieving of forgiveness is what brings about the transformation that is needed to save us in the end.
Without forgiveness, every technological development, new political structure, or monetary policy simply becomes yet another tool for inflicting damage on each other and the planet.
My two-cents.
