In the waning days of the Soviet Union, the Communist Party picked a series of ailing old men to lead the state. Without a free press, and with information about the government tightly controlled by a few, it wasn't unusual to hear that a leader was "doing just fine" one day, that he "had a cold" the next, and that he was dead a week later. Western analysts would comb through official communiques to catch the slightest clue as to what might be going on behind the Kremlin's walls.
There's more than a hint of this in the rather gruesome speculation has arisen about Steve Jobs's health on multiple occasions since his cancer surgery in 2004. Essentially, whenever Jobs doesn't do something he's expected to do, it's taken as evidence that he's dying -- even when the action is part of a larger complex of events, like his not making the keynote address at Macworld Expo next month.
It's easy to understand why people equate the health of Apple with the health of its cofounder, seeing as the company's decline and revival mapped fairly neatly onto Jobs's departure and return. But, as this Wall Street Journal article neatly lays out, Jobs has spent much of his post-return decade building up the Apple management team. It seems that a post-Jobs Apple (which could happen next year or in 20) will be a duller company, but probably still a successful one.