Facebook already knew this, that's one of the reasons why AT&T and HTC are included in this project, for HTC first device they will install it as system app which will avoid this problem.

Collaborating with HTC and AT&T allows them to install 'Home' as system app in future devices, this will allow their app to add 'layers' on top of any app. This can only be done if device is rooted or app is installed as system app.