When I wrote my above post there was two methods of open and closed i referenced. The first we think of is like maemo versus iPhone. Windows versus Linux. The second is Windows based computers versus Apple's Macs. Where both are considered closed if you use Linux but you can use Windows on more computers than you can OSX.

What is the benefit of the latter? Simple a bigger audience. You can make X dollars given a deal with Apple with the Y number of iPhone users. Or X dollars given the userbase of Y number of whatever OS which is found on alot more phones.

Right now it's in Apple's court but if it's anything like the PC market an "open" competitor that allows their OS to be used on more types of devices is going have more of a userbase, hence a bigger market to sell too. Right now all of Apple's competitors are still growing (Android being slowly adopted for more and more phones) or like Windows Mobile who have been slacking till Apple came on the scene.