Cook has been running the day-to-day operations of Apple for quite some time, if not necessarily officially, with Jobs' extended illness before his death. I'm not worried about the execution side of things.
The real question is whether Apple will continue to make the evolutionary leaps that have been the backbone of their success after the current pipeline of ideas peters out.
One thing is certain, though -- as long as its competitors continue to race to the bottom and place technical specs over user experience, Apple isn't going to lose its competitive advantages any time soon.
Your point about user experience is spot on. How many websites get the job done technically, but offer a horrible user experience? My understanding about Apple is that they cobble together existing technologies, in dynamic fashion and create new or vastly improved user experiences. The dynamism isn’t in Apple’s tech, but in their execution. If Cook is running with the ball and has been for five or more years then you’re correct about Apple being in great shape for the foreseeable future.
We’ve seen, though, other companies play the Q-results game. I hope the numbers are legit and like to see winners like Apple setting the pace.