As you've most likely heard from a thousand different places before you came here, and will almost certainly hear a lot more about in the days and weeks to come, Kim Jong-Il has died at age 69. North Korea is certainly the place to be looking at to right now; it's an unstable place under normal circumstances, and with a leadership change underway and a massive artillery pointed right at Seoul from a totalitarian state that has nukes (very poor-quality nukes, but nukes nonetheless), for the moment, the world has little choice but to stop dead in its tracks and pay attention. Nobody has any real idea what the new man in charge, 27-year-old Kim Jong-Un, is capable of, and nobody wants to find out the hard way.
I can't profess to tell you either. It is quite possibly the most important piece of information in the world right now and nobody really knows the answer. All anyone can do is speculate, keep their guard up, and wait to see what he does. It's fairly safe to assume, though, that what WON'T happen is that Jong-Un throws open the borders and pledges reconciliation with South Korea.
We do know that North Korea's neighbors are interested mainly in making sure there isn't a total breakdown. South Korea is all but certain that if North Korea goes critical, the fallout will come down squarely on them. China is thinking similarly. Their main worry is preventing a mass exodus of refugees from stampeding across the border, where they would then have to deal with them as they began a long end-run journey to South Korea or whatever country will have them. Whatever you think of China's stance on keeping them from crossing, that's their mindset. And given that the North Korean border guards can themselves defect, as happened in November, they can't count on very much help from them should such an exodus occur.
Japan isn't really sure what to think, but for the moment they're primarily watching their stock market, which responded to Jong-Il's death by immediately tanking due to the uncertainty. They do, however, have the issue of North Korea having abducted several Japanese citizens over the years; the families of the abductees are using the death to try to get the issue to the forefront.
We also know that, even though the preferred end-state all around is a peacefully unified Korean peninsula, nobody knows how to get there, nobody knows if such a thing is even possible, and above all, nobody knows how to prod a North Korean endgame into place without it backfiring into North Korea deciding to go out in a blaze of glory, leveling Seoul and taking it with them, forcing a bloodbath with possibly millions dead, and getting to the point where North Korean loyalists hide in the hills for decades afterward like the Japanese soldiers of World War 2 who were deployed to the Pacific islands and were never told the war was over. Maybe a nuclear warhead gets launched as well. Lacking a way to avoid the blaze-of-glory endgame, all anyone can do is maintain the status quo until and unless some sort of semi-safe solution presents itself. That, of course, has not happened.
We don't know much, though, and we won't know much until Kim Jong-Un starts saying and doing things. We never do when North Korea is concerned.
EDIT: Adrian Hong of Foreign Policy is willing to try to put together a roadmap to that semi-safe solution. It's a long, complicated road with a lot of blind alleys, and there's no way to make things go as quickly as one might like to make them go, and there are a thousand different failure points- which in itself underscores just how difficult a task it is- but it's a roadmap nonetheless.