There are only two things keeping the app store model afloat: curation and lock-in. Curation in the broad sense that people know where to go for apps for their platform, and it is a consistent, unified user experience, whether the apps are free or paid. Apps themselves aren't going anywhere, because there are some things apps can do that the alternative, websites, can't do. You need apps, and you need a place to get them.
But the thing is, curation can come from anywhere, and if someone else does a better job, customers will use it that alternative. That's assuming you can set up an alternative app store, which is the lock-in part. But even if you can't set up an alternative, you can always set up better recommendations, categorisation, searching and reviews with links to the official app store. Even if using your version is harder than the real one, that price of inconvenience might be worth paying.
Mokalus of Borg
PS - This is part of why Apple makes it impossible to set up an alternative app store.
PPS - It keeps them in control by force.