DAVOS, Switzerland — When can we stop calling China an emerging economy?

Top business leaders, politicians and social activists tackled this and a host of other issues as the World Economic Forum opened today amid a burst of optimism that the world has seen the worst of the financial crisis and now faces a “new reality.”

The 2,500 participants at this year’s annual meeting in the picturesque Alpine town of Davos are focusing much of their concentrated expertise on China’s growing clout, simmering anxieties about Europe’s debt crisis and consideration of the possible aftershocks of the financial crisis that has wrought layoffs, cutbacks and austerity measures.

With China overtaking Japan as the world’s No. 2 economy last year, and growth predicted to hold steady in the upper single digits this year, panelists questioned whether Beijing hasn’t already arrived at the top table.

“We have to get out of the lexicon the words ‘developing’ or ‘emerging,’” said Martin Sorrell, chief executive of advertising giant WPP Group.

China and India have sent their biggest delegations to this year’s forum, spearheaded by business leaders seeking to plant their flags on a stage previously dominated by U.S. and European companies.

“In 10 years the economies of the emerging world will be in excess to $20 trillion, which is equal to the U.S. economy,” noted Azim Premji, chairman of India’s Wipro.

Zhu Min, former deputy governor of the Bank of China, cautioned that the figures obscure huge expectations among the poorest in the developing world that cannot be met soon.

The theme of this year’s meeting is “Shared Norms for the New Reality,” and part of that includes the new economic reality, too.