One thing I think is "wrong" with this conversation is the attribution of qualities of how Apple treats their handheld division to generalized discussions of how Apple "works". Apple is much more open with their software on the desktop side than Microsoft. True, they don't allow you to run OSX on generic hardware (officially supported, it is certainly possible homebrew style), but otherwise, they are very supporting of open standards and even open source software on out of their desktop division. Darwin (the OSX kernel) is open source, as is WebKit (Safari), SproutCore, and a whole host of other frameworks and back-ends to their software. Many people look at the hardware lock-in as being designed to "protect" hardware sales. This may be true to a small degree, but I suspect it is more targeted at protecting the crash-free image of their OS than anything (which is then used to drive hardware sales). They control the hardware, and therefore it is easier to control the OS. There is no "driver hell" like Vista encountered on release.
In comparison, it took serious anti-trust enforcement from the EU (the US wimped out when the administration changed) to get Microsoft to release even appropriate documentation for their APIs for their OS. And they still haven't fully complied. They certainly do not release and support any open source software for any of their core projects.
On the flipside, with their handhelds, Apple is certainly on the other side of the fence.
I think it comes down to simple business decisions every time, designed to preserve shareholder value. Apple locks their handhelds down because they can and they'll still sell. Microsoft doesn't go quite as far because they can't (though their handhelds certainly aren't "open" in any sense of the word either). Period. Perhaps eventually Apple''s walled garden will fall down, but I think it will depend on Apple screwing up in a spectacular fashion, not on consumer demand. People have shown over the past 4-5 years that they just don't care that much, and that using iTunes+iPod is "good enough".