I still think that if China's loss of patience with the Korean dictator is genuine, he isn't long for the world.
A data point comes from Mr. Spog, who notices this article in the Korea Times. It seems the Chinese media is full of articles about how ancient northern Korean kingdoms were really part of China.
Apparently, this bold new direction in historical scholarship really got underway in 2003. Andrei Lankov, the Russian expert quoted in the Korea Times piece, thinks there are parts of the NK elite who would welcome some attention to their internal politics from their elder brother in socialism.