The North Korean Communist party rule is iron clad, but brittle. They literally can't squeeze their people any harder under the system they have now. If the people no longer fear death and imprisonment because they have found a dim sliver of hope, the government may well be doomed. This is not to say that a grass roots uprising is in the works, or would even be effective. It does mean that the government is losing control, and a climate where rebellious military units, officials or key personnel may be able to take advantage of the situation.
Among the 'elites', they may pay lip service to the high command, but if the peasants are learning the truth, they may want to position themselves to take advantage of what may come of it. Brutal but incompetent regimes breed clever, ambitious survivors. Many a stagnant Asian emperor has fallen before a bold, rebellious official, because of how powerful certain individuals are in the autocracy.
Given how extreme and terrible the rule of Kim Jong Il is, any rebellion or civic breakdown is likely to be sudden, unexpected, and unstoppable. If Kim senses that the whole system is falling apart, he may be motivated to try anything before he wakes up deposed.
See my No. 83 in this thread.