If Jong-un were to take over soon, he is likely to remain weak, vulnerable and at the mercy of the North's old guard for years, experts have said.
North Korea places great emphasis on seniority and the ruling elite around Kim Jong-il, mostly men beyond 70, are not about to take orders from the son, one intelligence source has said.
As tens of thousands packed into Kim Il-sung Square in the North Korean capital of Pyongyang, one image from Japanese news agency Kyodo shows a funeral cortege led by a limousine carrying the departed 69-year-old dictator.
However, a note released by Reuters describing the images said: 'This combination picture of two handout images from KCNA shows a limousine with a portrait of late North Korean leader Kim Jong-il leading his funeral procession in Pyongyang December 28, 2011.
Born in 1983, he is believed to have attended an international school in Switzerland under a pseudonym.
There is no adult photograph of him publicly available.
Bill returned to Louisville and joined WAKY in 1970, where he ruled the morning roost there through 1981.