I bought my first Apple back in 1984. It was a Mac, and until about 1996 I was a Mac addict. Did I buy the occasional Windows box, sure, but the bulk of my work was on the Mac at the house. Then I bought a Dell laptop, and it became my weapon of choice. I came back to Apple in the early 2000 era as I began to feel once again the Mac was the way to go. Now, I'm almost all totally Apple, and leaning more and more to just doing a Tony Soprano, and saying "forgetaboutit" to Android and Blackberry, other than to simply own them to evaluate client software and services that run on those two platforms.
Apple leads, and where they lead best is in the developer sector. Take for example how elegantly some new business card replacement services have launched and how well they work within the Apple world first, and then everything else. Now look at client CounterPath and how well received their Apple iPad desktop phone replacement is being perceived.
The point here is while Android diddles around with their Honeycomb tablet SDK and API's, and while their carrier partners fight with their hardware partners over feature and functional set, Apple's developer team makes it easier for companies to want to work with them. In fact, I would contend that Apple's single vision vs. Googles biforcated view of Chrome (web os) vs. Android (apps) is more of a hinderance than a push to getting to where the want to go sooner.
Apple recognizes limitations, and works around them, something that iMessage will do far better than RIM ever did with BBM. If RIM wanted to stay ahead with BlackBerry Messenger, they would immediately open it up, because at some point Apple will do just that with iMessage (my opinion.)
It's this kind of forward looking view that makes Apple different and it's why they're leading, while everyone else just follows.