This is a nice idea but the first thing that comes to my mind is the possibility of multiple apps doing the same thing and the ugly "Which application to use?" modal of android. That is obviously bad design and must be avoided, not that any better way comes directly to my mind.

Why is it bad design? Because it's annoying, and if you check "Don't ask again" the way to revert is difficult to reach and completely beyond whatever a user could possibly imagine. (Instead of a default applications list or something, the user must go to app manager, find the default application for this action and click the super-ambiguous button labeled Clear Defaults)

Mutually exclusive dependencies is also bad design as the user may have use for both storage applications.

On the other hand, extendable control panel is cool, and we must give more thought on it. One possible solution is to keep the simple applet and list all the relative applications in it, the way Windows Phone list the applications that can edit a photo, after clicking edit in the gallery, but that adds a useless step.

Any ideas?