Speculation about North Korea's leadership succession

KimJongUn6x4 Kim Jong-un (seated L), the youngest son of North Korea's leader Kim Jong-il (seated R), poses with newly elected members of the central leadership body of the Workers' Party of Korea (WPK) and the participants in the WPK Conference, at the plaza of the Kumsusan Memorial Palace in Pyongyang. Taken on September 28, 2010, this is the first-ever published official photograph of the heir presumptive. REUTERS/KCNA
In recent weeks, questions have abounded about the succession of North Korea's leadership, especially about Kim Jong-un, the youngest son and heir-apparent of current leader Kim Jong-il. David Straub, associate director of the Korean Studies Program, spoke with NPR's Mike Shuster about the scant bits of information on the younger Kim--much of it rumor--floating about.