Unlikely with all the puffing and strutting that they will really want to start a war...I agree w/BPSCG, the real danger from the North is in what they may be trying to peddle around the world.
While a war isn't impossible, here are some of the considerations:
Yes, they have a million man army. It is unclear, however, how good an army it is. Weaponry is likely to be old and untried.
Second, they have Stalin's problem. They put ground troops into the South, that million man army is going to find out first hand, even combing through ruins, that their government has lied to to them. It will be abundantly clear to any troops that get into the south that the standard of living there is far, far higher than in the north.
Next, it is like 40 or 50 million in the South to 20 million in the North.
The south and its allies have the more up to date weaponry.
The north doesn't have much in the way of a fuel reserve...they go south, they can't power their tanks, trucks, etc. for very long.
While they can launch missles, there is real question as to the quality and accuracy of their abilities. What they've been doing lately is for show. It is planned to a tee. They've got their best people on it, planning the launches, etc. for days, to make sure that nothing goes wrong (remember the long range missle back in December(?) crashed into the ocean, not what they wanted the world to see). The launching circumstances will be very different if they go south, for one thing, missles will be launched back on them.
They can't contest either the U.S. airforce or the Korean Air force.
China is no sure bet to support them this time, nor is Russia. China has to be worried about a growing, unchecked nuclear power to its south. Further, they are worried that an unchecked north could cause the Japanese to both re-arm and go nuclear. China wants to be the player in Asia, it is likely going to step up to this situation if, for no other reason, a massive new land war on the Korean penninsula will be bad for commerce and China's economic recovery.
Russia can't support or won't support the North like it did in the past. Why? Not because they're not sympathetic, but because Russia is now a more cash and carry economy. They likely will not be giving the north arms out of old friendship, especially as its trading relationship with the south has signifcantly expanded in recent years. Also, they too have to have concerns about a nuclear power and possible war on their far east border.
It seems to me that much of what is going on is internal. There is some sort of power struggle going on in the line-up to replace Kim. THe putative family heir is only in his early 20s, the military can't like the idea of him succeeding without more seasoning, at the same time, the military has proped up the Kim regime, help to make and keep it paramount in the country, it must be at something of a loss about what to do in a power vacume when there is no strong Kim family member immediately available.
They, of course, also could be completely bat-sh$t crazy, even suicidal. They could be itching for a war, collectively, if you will, having drunk the kim coolaide and thinking they can win it. I just don't see that as the case however, their intelligence about our side and the South is far better than ours is about them. They know that we could have nukes on the penninsula. They know that the weaponry is better. They know that the South's standard of living is higher...they may think that will make them soft, but the leadership has to fear that its soldiers will be exposed to the lie that is the regime.