Of course, all of you saying this realize that these exact same arguments were made about the iPod and the iTunes Store. The old example set by Microsoft back in the early days of the Mac and Windows is not applicable to everything. Every device does not have to be promiscuously linked to every company and product out there. That was true of PCs but, so far, we've seen little evidence to support the argument that it must be true for smaller, more limited devices to succeed.
You are correct about the iPod.
But we are also entering different times now: The iPod had by far the best UI in its segment, and iTunes was way ahead of competing systems. There simply no competition.
The same was true for the iPhone, until the end of 2009. There was nothing that could touch the iPhone in terms of UI and ease of use.
More importantly, there was never such anger among Apple users towards the iPod. The iPhone started to rile up users when Apple "bricked" some iPhones initially, but most of us learned to live with it, once jailbreaking became well-established.
The iPad and its pointed exclusion of Flash, as part of Apple's further tightening of the noose around its i-Captive audience were the last straw for me, personally. And I am certainly not alone, among long-time Apple users.
There is a perfect storm, IMO, as there is rising anger toward the walled garden (I actually believe that after the initial OS 4 jailbreaks, Apple will lock its ecosystems tighter, and jailbreaking will become much harder).
But for the first time, there is also a viable competitor, in Android 2+. Certainly Jobs took notice of it.
I've played with a Nexus One, and it's almost as good as my 3G S. By 2.2, with full Flash, Android should be as good as OS4 in UI, and better because it will have a full browser (with Flash) and it will be more open. The apps I use are already on Android, and look and work the same as on the iPhone (I guess that's why Jobs banned crosscompilers).
The same is with tablets. Normally, I would have jumped on the iPad. But now I am holding out for one of the Androids coming out.
We'll see what happens. I personally feels Apple has become too arogant, and Jobs has picked too many fights, with Google, Adobe, and most importantly, his customers.