I'm afraid the Apple faithful are playing a little fast and loose with logic on this one. Let me see if we have this straight...
1) Steve Jobs was absolutely and almost singularly responsible for Apple's meteoric rise over the last 14 years. His vision, his taste, his standards, his business acumen, all of it - has driven Apple past competitor after competitor to become the most valuable company in the world. [By the way, I agree.]
2) Steve Jobs is also completely unnecessary for Apple's continued success. [Hmmmm]
I think I can agree with Gruber's wisdom in choosing to prognosticate no further than a month. What made Apple remarkable is going away today. From here on out Apple will be as likely as the next company to blunder in the marketplace by playing it safe. You will not see Tim Cook do anything half as insane/brilliant as Jobs was capable of.