Yes, we are becoming more centralized because the world is becoming more complex and interconnected, requiring more done by the government in general and more of it done by the central government. We can't possibly know how far it will go. We can no more imagine the world in the middle of the 23rd century than the Constitution framers were able to imagine ours (just one bit: back then the 10 biggest American towns and villages - there were no cities - had the combined population about the same as modern Peoria).