The best case scenario, aside from Koizumi beating them in a mahjong game, is Dear Leader dying and being replaced with someone more moderate. It's a really sticky situation, and I have a bad feeling it's going to get pretty ugly if North Korea doesn't stop their shenanigans.
I think you underestimate how much of the country's stability is based on fear. Moderation implies the ability to dissent. North Korea is what most Communist states would look like today had they survived the 80s. Unbelievable economic disparity. People living at the subsistence level. Almost no education. Almost no infrastructure that doesn't relate to military production. No modern services. (I think Doctors Without Borders was allowed in to do cataracts surgery....because NK can't even train professional doctors or get the equipment they need to do it themselves. Watching peasants who haven't seen in 20 years weep and cry and thank a photo of the Great Chairman, while party officials stand by and note their level of gratitude.....yeah. That's North Korea.)
Meanwhile, they have an absurdly large military and have managed to invest in nuclear power.
The only way a country has functioned like that is when you have the people completely under your boot. Germans enjoyed a comparatively high quality of life under teh Nazis, compared to North Korea. Hell, even under the Communists and that's saying A LOT.
If you bring in a moderate leader, one trying to ease restrictions while retaining the old government, all those societal cracks burst open. People flood to the border in an effort to escape 50 years of oppression that almost no one knows the full scope of. Overnight NK collapses in on itself.
A moderate leader implies they retain some of the old leadership styles. That's not going to fly, I think, were it to ever happen. They have been through too much shit to make the change gradually. I think the first opening of real freedom would basically turn into a stampede. So. I think they need a modern leader who totally abandons the old ways of thinking and tries to integrate North Korea into the rest of the world, while retaining their national sovereignty (since that's all North Koren have).
The only way you get that kind of leadership in place is with a revolution. Very, very few communist regimes went quietly, and they were moderates compared to North Korea.
Honk if you find our resident armchair commanders cute.
Not as cute as your avatar Chairman.