North Korea is an area of my research; what I can tell you is that we were unclear on the nature of the death of Kim Jong Il's father and forerunner until roughly a decade after it happened, and even now we just have suggestive bits and pieces; his father supposedly had a heart attack in a luxury hotel in a remote location where no medical assistance could be rendered for over two days, then after he died, two of the four helicopters carrying his cabinet mysteriously crashed with no survivors. There was a three year gap until Kim Jong Il was named Leader, which North Korean history now recounts as the "Period of Mourning", however more objective history notes that many high-level officials went missing or committed suicide during this period - there was obviously a great deal of very deadly jockeying for position even though Kim Jong Il was supposed to naturally inherit the position.
If history is any guide, expect North Korea to name a temporary interim military leader (possibly Kim Jong Il's recently promoted sister Kim Kyong Hui) then remain silent on any further news about the government for a very long time.
If you own a shortwave radio, you can get the official news firsthand from the Voice of Korea at 9335 and 11710 kHz at 1300-1400 hours UTC, but expect most of the programming to be tributes and (party line/not actual) historical in nature.