Essentially, Apple is a one product company. That product is "the mac". The "mac" comes in the form of a combination of software and hardware. OS X on Macintoshes is the past, iOS on iDevices is the future. All of that is Forstall (if I'm understanding things right.) And even then, the hardware is merely the box for the software. They make a very great box.
But Forstall is the "new jobs" in that regard. Ive can demand that it have fewer buttons, and Schiller can demand that marketing be on message, and Forstall has to listen to them, and if he doesn't then Cook should have their backs. Cook is thus well placed to be the "vision guy" (and yes, I think that is a legitimate description and that he'd be just as good as jobs at it) whose got his finger on the daily operations but also is looking 5, 10 & 15 years into the future.
Apple University is the glue that holds these four guys together and keeps them on the same page. Plus, of course, The Writings of The Chairman from Jobs over the years.
In fact, I would bet good money that there literally is a book within Apple, that probably only has a dozen or fewer copies, written by Jobs about the Apple Way and presenting his vision for the Apple Way. In a way, his living will to the future.
I think this book is Apple's equivalent to Cokes "secret formula", only Apple doesn't trumpet that they have a secret formula, they keep even the existence of it secret.