OFK's Joshua, with some fancy keywork and must-read links, has reached the depressing conclusion Left Flank did already, but with much more rending and gnashing:

...we haven’t paid enough.  On the “disablement” of the already used-up Yongbyon reactor, there seem to be legitimate technical reasons why disablement has slowed down, but North Korea is also deliberately slowing things down.

There's just enough tea leaves to invite a broad range of conjecture, but, like a Rorschach test, I think Blake Hounshell has a more useful take on Pyongyang's "temper tantrum":

Perhaps there's something more nefarious going on, but Occam's Razor suggests that an impending famine is the main reason for the North's latest tantrum. Until the country's leaders learns how to address such problems in a forthright manner, I'm afraid, this is the kind of thing we can expect.

OFK likes to examine the bureaucratic and the personal: I prefer the systemic, how states interact regardless of who or what's behind the curtain. But, Hounshell's fits with Beijing's recent "natural" admonition. Perhaps, Beijing is correcting for any rosy interpretation of the Fukuda visit, and there's always reminding Taiwan of its diplomatic vulnerability. Weekly Standard's Michael Goldfarb even argues Beijing sneaks a zinger at democratization on the Kenya issue, even when the ethnic fiasco has past governments' stinking paws all over it. Anyway, I think the Bush administration is just outclassed.

Related to this, both TMH and DPRK Forum are excited about "Keeping an Eye on an Unruly Neighbor", and the TMH boards are both spirited and informative. But, I would argue that Beijing's long list of policy options, the contingencies it has planned into perfunctory procedures, is irrelevant to this goal to keep DPRK as a bargaining chip in the region against the US and Japan. And, DPRK's punky determination to stay alive and muddle through (coupled with the region's need to keep giving it life support aid and rice) just makes Beijing's task easier. If it all fell apart tomorrow, kudos to those who chanted and danced to widen the cracks in the pavement, but it's more impressive how the jerry-rigging just seems to work oblivious of all the prayers directed at it. As Michael Garibaldi said, Daffy Duck is the "patron saint of frustration".

But, Jack at DPRK Forums has a better read of the inkspots for my money:

I do not have a crystal ball, so it is very hard to say what the future may bring. Whatever the case, sudden collapse will be painful and a mess. I cannot see it any other way.

Even, Andrei Lankov has to admit it:

But again: over last three years I keep saying that collapse is likely, but there is a force which is perhaps capable and willing to prevent it, and this force is China.

As Robert Koehler quoted:

Don’t think Beijing will be getting into the regime change business anytime soon, though. One Chinese expert told the team, 'We don’t care who is in power as long as stability is maintained.'

Any attempt at wishing that away is to invite another Iraq, an even worse miscalculation, if that's possible.