Amid the arrival of presidents, prime ministers and kings, the 66th annual session of the U.N. General Assembly debate opens in New York on Wednesday, but the session hardly starts in a celebratory mood as a series of geopolitical, financial and natural jolts have shaken the world body to the core, including the "Arab Spring" of 2011 and debilitating natural disasters.

To the foreboding backdrop of a global economic upheaval and major political changes in the Middle East, the session's elected president, Nassir Abdulaziz al-Nasser of Qatar, stated perhaps prophetically, "The sands are shifting." He added that "political protests were upending once-stable governments, and the seemingly unending raft of natural and man-made disasters," were reshaping the global scene for the 193 member states.

Though the U.N. General Assembly will plod through its near-static 168-item agenda over the next few months, the real focus of the session comes down to a few key issues; the Arab Spring, the global economic gloom, and the humanitarian challenge of natural disasters from Haiti to the Horn of Africa.