The passing of Hugo Chávez provides a moment to consider the question of the waning of the Communist era. The history of the origins of the Industrial Revolution that I've been reading led to that question.
My tentative answer is this: I suspect Communism, while it played a major role in the 20th century, will be hardly remembered by historians 500 years from now. After all, it was a blip empire that lasted about as long as a human life. Its significance, I am guessing, will be seen as just one spinoff from the Industrial Revolution. Maybe like global warming but far less important.
In sum: Communism may be the Albigensian heresy of our time. Sure, that belief system covered a smaller geographical area (but I think a larger chunk of the known world). And there is no question that it lasted much longer.