Looking back at the last hundred, it is clear that unforseen events, such as the rise of a Hitler or the discovery of atomic fission, can drastically alter world events.
But since we can only look at the obvious, I think world corporations will have a tremendous impact on the future, as will fundamentalist religions, especially Islam.
China will likely become the next superpower and possibly be the next America as it has a huge population, high work ethic and abundant natural resources.
I think that globalization will continue as contries continue to agregate to survive, probably along continental boundries.
I think a nuclear war of some type is inevitable (possibly between India and Pakistan), which means that some type of environmental backlash will occur.
Technologically, I think we will eventually solve the energy crisis which will allow several other advances (such as moon colonization), but that we may continue to lose our biological diversity (and may regain it through advances in genetic research).
So that is my fancy way of saying I don't know
