It's remarkable to see Apple once again in the position of selling a whole-stack platform (software and hardware, at least -- network sold separately), competing with a broad coalition of commodity hardware companies using a common software platform. I think they'll repeat history -- they are already repeating history -- by not doing whatever they can to bring developers to their platform.
Sounds intriguing, but I see one possible difference: in the PC world there is pressure to do what your peers do in order to swap software. In the mobile world this has not happened, yet, and maybe never will. The peer pressure in the mobile world, if any, is to keep up with the user experience of your peer's mobile. So maybe the comparison above does not apply.