I think it will happen. If you look at the free nations of the world, things get better with every generation. The internet is exposing people in oppressed nations that they could be free if they took down their crappy leaders. When all the nations of the world are free then we will naturally melt together. We will never get rid of the different cultures, but every generation is more tolerant than the last so eventually all the different cultures will get along and except the differences.
What would really get things moving in the right direction is a universal language. I vote for English because it's versatile and I wouldn't have to learn a new language.
I've always wondered why each language has it's own brand of sign language. I mean nearly everyone on the planet can nod their head for yes or shake it for know and it doesn't matter what language you speak. Shouldn't there just be one sign language? If there was one universal sign language and everyone on the planet learned it as a kid we would all be able to communicate with each other with at last sign language. Not only would we all be able to communicate with the deaf we would be able to break all language barriers. It's a win win.
