Sorry, but this whole analysis misses the Steve Jobsian point of product development. It's not about the technology itself -- it's about the end user experience.
Yap all ya like about Linux and PS3 and the Cell and all that jazz. But so long as Steve Jobs or someone born of his mold is sitting at the top and maintaining a vise-like grip on product development -- and fanatically focusing that development on the end user experience -- then all the rest of the elements should fall into place and Apple will remain a leader either in design and thought (Mac OS X) or in actual market share (iPod, iTunes).
The problem with Windows and Linux is that no one controls the end user experience with enough vigor and attention to detail. Windows is doing better and better with each revision, but there are still too many cooks in that kitchen. Linux has no central leadership on the end user experience because it cannot, by definition, be uniformly led or controlled by any one person or group. All that said, Apple still has some cleaning up to do in its Mac OS X camp -- the Finder and lots of their bundled applications do not yet behave uniformly or maintain a consistent look/feel. So even with Jobs cracking heads, Mac OS X still has issues, but it's way out in front of platforms with no one leading from a position of end-user focus and authority.
As for the shifting-processor threat, Apple is now successfully moving its Mac OS X platform into a processor-agnostic model. Follow their mantra -- use Xcode, use Xcode, use Xcode. They know they might have to jump processors again, and probably expect to jump. Stick with their development approach (Xcode) and you'll be able to follow them wherever they go. If they have to go to Cell, so be it. If the go to the Sun 8-way package, so be it. They've gotten it right at this point -- the presentation layer is the best in the business (though it could be better still), and the development layer has been largely abstracted from the hardware layer.
And puhleeze stop with the Linux predictions of growth or dominance or whatever. Linux is a great OS, but it's impossible for end users to use -- no applications, nothing is easy, and there are a billion variations. Way, way, WAY too hard for end users to handle. And that will not change because no one's in charge of it. Again, great OS, but only when it's handed to end users in a closed package (like the proposed PS3 setup).
Apple license OS X? Not likely. The only way that works is if they have a massive hardware certification program or license only specific manufacturers that stick to their straight and narrow hardware path. It's easier to make your own to your own specs than to hammer out contracts with third parties (like a Dell) to make things that meet your exacting standards. Keep in mind that Apple doesn't really make any of their own hardware anymore. So why contract with Dell when you can dictate terms to a Taiwanese manufacturer and get your preferred solution, then sell it yourself and get the best margins? End user simplicity and stability is the point, and that's impossible to maintain when Dell switches hard drive, processor, memory and DVD-RW models and suppliers every week.
Sure, Apple has challenges, as do the rest of the companies noted in the analysis. I just don't buy the overall concept that 2006 is Apple's high water mark and 2007 begins the decline. I can look back in history and see a lot tougher business environments in which Apple has done just fine, thank you. After all, the biggest story about the Intel transition is that it's not much of a transition at all. For the end users. And that's the point.