My personal prediction is (if we manage to make it that far) that the world will first start coalescing into supranational states such as the EU and African Union, after which these states will merge into a international superstate. Idk what timeframe this would be in, certainly not within our lifetimes, and who knows what kind of shape they will take on, but I feel like it's inevitable.

Another thing I was thinking off is that probably all of the world's cultures and languages will merge into one. The reason they exist at all is because of the fact that communication and travel was extremely difficult on any sort of distance thousands of years ago. With the advent of the Internet and faster travel methods, I feel like its only a matter of time before all of the world's cultures melt into each other. I'm sure there would still be minor regional differences, but it's probably gonna be much more uniform than today.