The bank warned that, "serious tensions and pitfalls" remain in the global economy, such as Europe's debt crisis and volatile international capital flows, which "could derail the recovery," the World Bank report said.

"If the financial crisis was a kind of a stress test for the developing economies, then they passed that test with flying colors," said Hans Timmer, director of the World Bank's Global Economic Prospects 2011 report.

China's growth will temper to a still-steaming 8.7% in 2011 from 10% in 2010. India is set to grow by 8.4%; in many sub-Saharan African countries, growth is expected to exceed 6%.

Rich nations, meanwhile, are still struggling in the aftermath of the global crisis. Growth by wealthy nations in 2011 is expected to be 2.4%, down from 2.8% in 2010. This won't be strong enough to significantly reduce high unemployment and spare capacity, the bank said.

Developing nations' rebound was all the more remarkable because it was also based on internal growth. "Their import growth is much faster than their export growth," said Timmer.