How I think the world will look like come 2040.
Europe
By this time, I think the European political, social and economical integration will be deep enough to the point that the whole union is represented by one seat in the United Nations. It will also expand to all the states in Europe with the exception of Belarus, Russia and Ukraine.
UK is separated from the EU because it's my map dam it!
Turkey eventually gives up on getting into the EU and settles for an associate membership, forever bitter and resentful of the EU.
I think Belarus will be admitted into the Russian Federation as a republic. In my head, it goes something like Lushenko dieing, his chosen successor rigs an election and the people and the some of the army, fed up with the government riots and protests. Then some Belarus generals will invite Russia to restore stability in which the Russian Army enters Belarus without resistance. Something like Britain's Tumbledown Dick + Glorious Revolution but Belarussified. Then Russia conducts a smoky but not confirmed referendum that admits Belarus into Russia.
Ukraine descends into a civil war between the Pro-EU faction and the Pro-Russia faction after the assassination of the Prime Minister that begins Ukraine's integration into the EU.
MIDDLE EAST
The Arab State begin to unite politically, economically and socially but not from the Arab League but rather, The Cooperation Council for the Arab States of the Gulf. It starts with all the rich Arab nations in the Gulf, Bahrain, Qatar, UAE, Kuwait, Saudi Arabia, Oman and then it starts to admit in the richer Arab nations as time passes. I believe that by 2030, Lebanon, Jordan, Libya (Once, al-Gaddafi dies and Libya switches from Pan-Africanism to Pan-Arabianism), Algeria and Tunisia will be rich and developed enough to be admitted into this Arab State. Yemen and Iraq are in because in my mind, Yemen finds a whole lot of oil at Socotra and Iraq experiences a Post-War Boom, a Miracle on the Tigris like Japan, Korea, Germany, yada yada. Egypt and Syria are associate members but are currently not fully integrated into the Arab State until they become more developed. Morocco does not want to join.
CENTRAL ASIA
Russia's integration of Belarus and increasing Chinese influence leads to the banding of all the Turkic States in Central Asia. First it starts off as a Customs and Market Union, then throw in a common Passport, then a united Defense policy and before you know it, bam! Welcome to the Turkestan Republic. While Turkey remains close ties with Turkestan, it stop short of a true union.
SOUTH AMERICA
South America develops into the Andean Community Bloc and the Mercosur Bloc. Just like the Turks, their economical cooperation later become a political union. While Mercosur becomes more united politically, I think Brazil will stop short of such a union but maintain high Economic ties. Venezuela is deciding between Mercosur and the Andean Community.
CENTRAL AMERICA
Two blocs form, the Caricom and the Central American Republic. They follow the same steps as mentioned above.
AFRICA
Sudan should be split into North and South Sudan. Not done on this Map.
The East African Federation comes into reality.
I don't know much about Africa so the only other two unions I can see possibly happening is the Union of Southern Africa and the Republics of Congo.
ASIA-Pacific
Korea becomes united under South Korea. Though its more like a Nation-Protectorate/Giant Concentration Camp kinda thing.
Australia and New Zealand become one Country. Singapore, Brunei and Malaysia apply to join this union. Might Succeed.
A Pacific Republic is created for many of the Pacific Island nations. Their Navy is wicked.
Most countries in the world either fall into the influence of one large Superpower nation or bloc or the other. Those who are strong enough not to be influenced are:
Philippines
Indonesia
Japan
Korea
Thailand
Vietnam
Myanmar
Pakistan
Iran
Turkey
Ethiopia
Mexico
Canada
Nigeria
Most of these nations share the following in common:
Strong National Unity
Medium to Large size nations
Huge populations (over 50 million as of 2010)
large and Strong economy or potential to be a large and strong economy
Many Natural resources.