I know it's been discussed, but Al-Jazeera's article about China's view of North Korea has this interesting nugget:
http://english.aljazeera.net/news/asia-pacific/2010/11/2010113034727624560.htmlThe cable said that Cheng suggested that Kim Jong-il's decision to anoint his youngest son as his successor was driven more by Kim's deteriorating health than any carefully planned strategy.
"They had no time to plan for this," he was quoted as saying, adding that Kim Jong-il's announcement was designed to send a message to the military that he held the power.
...
Chun was quoted as saying that he believed that the North would cease to function as a state within three years of Kim Jong-il's death