What if app stores were federated?

I've been thinking a lot lately about the future of software and where native apps and the web will reconcile and I had the idea that what if "the next OS" had a OSS federated app store that people and organizations could host themselves, but the system still used the app store model that pull app/program listings from all the installations online? This could apply to mobile or desktop computing, or even any of the other platforms (see windows store system compatibility).