Someone will get the movement going within the next 10-100 years. I would like to see it happen peacefully but knowing the nature of the North a war could happen. It wouldn't be anything like the game Homefront though, where Korea would takeover America and the world. Only time will tell
It will definitely happen sooner or later. I believe that it would probably be through war rather than negotiations. The DPRK is losing favor from their longtime ally China, and I believe that when war between the South and North sparks, China would not be there for North Korea. They would be defenseless with their weak military.
The North and South have been separated for nearly 60 years now. Even if they had a similar history at the time, their current cultures are radically different now. That problem will only get worse as time moves on. And it is very difficult to get two completely different groups to come together into one coherent body. And to come together peacefully without one dominating the other, they need to be on equal ground. This means the economy, standard of living, and human rights need to be raised in the north or lowered in the south. If they are not equal one will control more power in a unified Korea, which will alienate the other, causing friction to build between the two sides until they break. And military conquest wouldn't work either because the north has nuclear weapons (which are a great deterrent to war)and refuses to give them up and the south has the superior economy, military, and allies. If these nations could work through their differences and reunite, it will be far beyond our life times.