North Korea rattles sabers, demands attention, candy

[Black Aeronaut]

If North Korea can get a nuclear warhead to Japan, I will eat my shoes.

(I don't own a hat.)

http://en.wikipedia.org/wiki/Taepodong-1

And Tokyo is well within its range when carrying a 1,500 kg payload. 
How would you like your shoes, Valles?  Might I recommend marinating
them for about a week followed by several nights in a slow-cook oven?

If
China conquered North Korea they'd be stuck sharing a border with the
US, and avoiding that danger is the whole point of their propping up
North Korea in the first place. Even when that danger goes away (either
by South Korea declaring independence or by the inevitable collapse of
the US empire) I can't see why they'd want to bother--it's better for
them to just cut off support for North Korea and let it be South Korea's
very expensive problem.

Um... the hell?  Look, it's not really what you're saying, it's how you say it.  Really, it's more like a collection of empires and each of them are still out trying to carve out more of the pie for themselves while us peons try to fight against it.  And don't gimme any BS about most Americans being in the top 5% of the world - it's hardly the point.
As for China... Well, I guess you might think that, given I referenced Shock and Awe.  But not that way.  China would prefer a puppet state.  One they could run without really running, you know.  So, while they'd hit the DPRK hard, it'll be nothing but their military assets, and I'm pretty sure the Chinese military knows where to hit them the best.  After the new government is in place (C'mon, face it.  This is China we're talking about.  They'll have new heads of state in place before you can even say 'rigged election'.) there won't be much of a new military build up.  There will be a lot of new trade as DPRK is now a much more friendly place.  And once the GDP goes up enough they'll start buying only Chinese weapons to update their sorely technologically repressed military.  Not a build up per se, just an overhaul of the hardware.
This would be the most desirable outcome, I think... but unfortunately, I don't think its gonna happen, because that would be like China taking responsibility.  And we all know how they are about that.
EDIT:  I'd like to apologize to Catty for not noticing that he Ninjad me earlier...

My thought on blackareonaut's thoughts;

1) North Korea is not in any shape to pay reparations, especially not
after a war. The reparations would have to come from China.

2a) This could go badly, very badly indeed, but I also see it as unlikely.

2b) Even if the USA acquiesces I see this going badly. Potentially a new
cold war which would wreck the now integrated global economy.

3) I the world wishes to stick to non-nuclear retaliation this could
happen. However the official policy in case of a nuclear attack is a
nuclear counter-strike, and I can see this happening either immediately
or more likely after some long drawn out discussions in the UN. If North
Korea launches a nuclear strike I give it good odds for the country to
be glassed in retaliation. Most powers in the world would be clamouring
for such a harsh example to be set.

Agreed on all points, even Number 3...  Though it would be nice to think that if it happened while Obama is in office that he'd refrain from pushing the Little Red Button(tm).
I think the 64,000USD question is... would China retaliate on the DPRK's behalf?