Time to rethink the mobile OS as a whole.
You want to do something with an image, for example, and you're greeted with a huge list of apps that all claim to handle images. Not only is it hard to find the app you want, most of the ones in the list have nothing to do with the task you're trying to accomplish. Hardly user friendly behavior.
FWIW, I personally don't really mind the huge list and can find my way around it, but I'm a heavy Unix user that does most of his work in the terminal already. Most consumers are not.
Apple had once an approach to this in the old Classic OS, by a switch that would enable or disable some access and features in the OS (esp. Finder). While this wasn't a great success on the desktop (like any other easy-suites), it might be worth to rethink for the mobile platform.
(Edit: This would also afford to expose system calls to the end user, being the end of consumer haven.)