So what of Jong-Un, a 26-year-old Swiss-educated basketball fan, becoming heir to the North Korean communist dynasty?
South Korea's intelligence services have received word that Kim Jong-Il has nominated Jong-Un to succeed him, a South Korean lawmaker briefed by intelligence officials said Tuesday. North Koreans were reported to already be making pledges of loyalty to Jong-Un and singing songs in praise of "General Kim."
Kim's third son has been described as a "chip off the old block" and is seen by experts as a potentially skilled and ruthless leader, like his father, who has kept his regime in place despite years of famine and economic decline.
"Jong-Un is known to have the potential to become a strong, ruthless leader. He has a take-charge personality," Cheong Seong-Chang, a North Korea expert at the Sejong Institute, told AFP.
Kim nominated Jong-Un as his successor some time between late last year and early this year and has been informing the party, military and the government of his choice, starting from the top echelons, Cheong said.
Kenji Fujimoto, a former Japanese sushi chef for the North Korean leader, described Jong-Un in a memoir as a "chip off the old block, a spitting image of his father in terms of face, body shape and personality."
"If Kim Jong-Il is gone, the possibility of the North bargaining away its nuclear weapons would also disappear as no one but the current leader would be powerful enough to browbeat the military," Cheong said.