Speaking to "This Week" host Christiane Amanpour from a huge military parade in Pyongyang marking the 65th anniversary of the North's Communist party, Woodruff said a general sat between the Kims and saluted both of them in a "first indication that he [Jong-un] could be actually in power here one of these days."
Woodruff said Kim Jong-il was limping and looked like he was "getting older every single day."
Kim is rumored to have had a stroke and to be diabetic. Very little is known about his youngest son, who is 27 or 28 and was educated in Switzerland.
Later on "This Week," former Pakistani President Pervez Musharraf staunchly denied U.S. contentions that Pakistan is not doing enough to fight terrorist forces.
"Don't generalize the statement that the Pakistan army is not doing enough," he said. "They have suffered over 2,000 casualties. What do we mean by not doing enough?"
Musharraf, in self-imposed exile in London, is planning a political comeback in his homeland.