When this is the case, I don't think that closed systems can or should be tolerated. Phones will simply be too important and too central to everyone's life to allow for this.
This is why I'm hoping that Android (or some other similarly open platform) gains a prominent place in the market, showing the rest of the industry the way forward.
Plus, cellphones are much more seen as appliances than 'computers' (at least today). As they get smarter, so do videogames, DVRs and other appliances - and still, there's no rush for making any of those electronics 'open source', nor claims for intolerance.
Android has an edge since the company behind it knows how to make software - I'm not convinced, though, it would be any different if Google did it all closed-source...
On Windows and OSX you can install and run whatever application you want. You can, without permission from Microsoft or Apple, develop whatever application you like and distribute it in any fashion you wish. This is the key difference between the iPhone and "computers" that I was trying to highlight.
It might be a closed system now, but give it a few years; I don't see any reasons why a cell phone (small computer, really) will remain closed for long.