One of the reasons that it is so difficult to get people to switch operating systems (or even to upgrade them) is due to the fear of erasing their existing OS and data. Even after a full and careful backup this fear still exists.
Most other operating system are either OEM installs or perform in place seamless upgrades. As far as I know no one has attempted to do in place P2V.
The idea of this is simple: When we detect a previous OS upon installing Fedora, offer to convert the previous installation into a VM image and set things up so that it is readily available to be run from the desktop.
In practice, this may turn out to be difficult to do for some proprietary OSes.