Lets take a look at the three companies and weave in the Open Source movement this week.
Apple: Its all about Jobs
This bleeds through several of the unauthorized Jobs biographies that Apples successes, and to some extent its failures, are all about Jobs. Steve, with all of his faults, can grasp quickly the core aspects of a successful product and communicate them very well. In addition he has a passion for excellence in his staff and has demonstrated a capability to drive them to do things that should have been impossible. But, at the core of all of this, is that Apple is a product company and lives, or dies, on the success of its lead offering.
Currently the lead offering is not a PC but the iPod, and Apple has even removed the Computer part of its name to reflect this change. But a product like an iPod has a limited run, something Sony (Walkman) and Palm can attest to. Eventually the market grows tired of it and moves on to the next big thing and, it is generally another company that provides it.
AppleTV has not been a hit (to be fair nothing else in that category including Microsofts offerings have either) and Apple is now betting on the iPhone.
This could be a serious problem for them because the iPhone breaks some known rules with respect to what has been successful historically. It has poor battery life compared to the iPod (and no replaceable battery), it is relatively large, it costs nearly 4 times what other phones in its class cost, and it uses a touch screen, which is known to be unacceptable for those that text messages. Like other Apple products it has a very clean UI and Industrial Design and it will be backed by Jobs, but it showcases Apples do it alone disadvantage. It mirrors to some degree the same mistake Sony made when they first tried (they later successfully partnered with Ericsson) to go after the cell phone market alone. In an established market, you dont need to learn by experience.
With Leopard, slated to be Apples run at the Enterprise, we may see this same problem in spades. The Enterprise market is very mature and Apple is no longer considered an Enterprise class vendor. To make a similar move a few decades earlier Microsoft partnered with IBM, and a decade ago Palm did as well, even more recently RIM partnered with a number of enterprise firms (these partnerships did not go well) to help them penetrate this space.