What's make me curious - do you plan enable option for selling apps? As a developer I would be more than happy to allow user install my app, but since I am not charity I would like to earn some money on it as well.
Yes, we'll have an app store much like iPhone/Android. Open source apps will have the option of using a "pay what you want" model, but we'll also allow proprietary apps with fixed prices and maybe even subscription-based.