I've been wracking my brain trying to think of another executive who passed at the absolute peak of his wealth and fame, as Steve Jobs did. This is the best I could come up with -- Irving Thalberg.
Of course even in that case Thalberg had been aced-out of his role as sole head of production five years before his death. (He had suffered a heart attack at age 33 and died of pneumonia in 1937.) So maybe even that's not a true analog.
But it's true that the studio closed the day of his funeral, just as Apple stores did yesterday in celebration of Jobs. Both Thalberg and Jobs were cultural icons, people who transformed the consumer world (as opposed to the Watsons of IBM, who worked with businesses).
If y'all can come up with a better analog, let me know. Elvis was fading when he passed at ae 42, and Lennon's star was 10 years dimmed when he died at age 40. John F. Kennedy comes to mind, but he was shot -- he didn't die of cancer, age 44.
It's a puzzlement.