Currently the world order is US hegemony. Prior to that it was the Cold War duel-superpower model. Before that we had no superpowers and a lot of major powers.
Here's a puzzle for any would-be economists and foreign policy freaks out there:

While development in the third world is increasing over time... would a different world system make development more efficient and equitable?
During the pre-Cold War days, there was imperialism and colonization... which carried many negative consequences... but overall began the development of many colonies that lacked the reesources to develop themselves.
While India is new as a major power and strong economy... it is initially a product of British imperialism... as are many strong developing nations.

During the Cold War the US and USSR were actively involved in winning over allies through development and protection pacts and other methods. These too had a lot of negative consequences... but it created a certain evenness to development. While US allies developed faster, USSR allies did have some development.

Much of our foreign policy today is Cold War aftermath... cleaning up the negative consequences of past world orders and maintaining the Cold War mentality despite the lack of USSR.
Nowadays development is mostly US-focused... but it seems US public sentiment is moving away from internationalism.
Of course China and the EU act as alternatives and compete with the US in development... but not in the same way as the USSR. The EU are basically our friends and China is interdependent with us.

So which world orders do the best for development? Which create the most counterproductive side effects? And which has the most potential?
Does intense competition help the cause or hurt it?

My thought is that the pre-Cold War system was the biggest jump in development. While certainly wicked, colonization (specifically that of the British) did lay out the blueprint for what nations are the most developed today.
The Cold War model was fairly productive... but its costs were greater than its benefits. The paranoid and opportunistic mentality of the Cold War led to short-sighted and terrible investments, not to mention a whole lot of fairly evil actions. The consequences range from horrendous regional unrest in the Americas and the Middle East to worldwide deep fissures between old alliances.
The current system of hegemony would not be as productive if hegemony was pure. With less need to build allies (at least mentally) the US is likely to do less to help the developing world. Most of the work at development is done by businesses, which act in their own interests. Their development is uneven and limited.
But I see potential.
China and the EU compete with us for influence even while no Cold War exists. Even Russia and Iran seem to be getting involved.
This, I think, will lead to the competition that will cause a more even distribution of development (even Africa is getting development, mainly due to China's "invasion" and the reaction sure to come from China's rivals). The competition exists but without the usual fear of destruction that was eminent in the Cold War.
When we come to realize that development is the best weapon in our "war on terror" and completely ditch the Cold War thought process, I think we will see even more development.

The problem:
What happens if China's influence indeed becomes too big? It would start another Cold War era world order.
I feel that the EU plays a crucial part in maintaining a balance with China. If China does grow to superpower status, the EU must grow with it.
I think three large powers that are interconnected shows great promise as a system for mutual world improvement.
Three creates a need for coalition. There are no even teams and it is less likely war would break out, cold or otherwise.
It also would even the distribution of responsibility to develop the world.

But in the meantime, limited hegemony works... provided that competition remains and no new Cold War breaks out.
The "war on terror" as it has been defined is the biggest barrier in the way of world development... Ironic since development is the best weapon at our disposal in that "war".

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"Man lives in the sunlit world of that which he believes to be reality. But unseen by most is an underworld, a place that is just as real... but not as brightly lit... A DARK SIDE!"
-opening from Tales From the Darkside