Jim the purpose of the beta is mostly for IT people to evaluate and familiarise, this prepares them ahead of the commercial release.
The general public are invited to try the Beta version also, and Microsoft encourages feedback from all Beta users so that any issues can be addressed before commercial release.
It isn't recommended for installing on your primary 'everyday' computer.
The beta expires in August, there will be no rolling back as you are advised not to go the upgrade path over your everyday OS.
Removing the 'For testing purposes only' notice which appears on the desktop will only happen once the commercial release is installed.
I'd assume that the commercial release could be used to upgrade the Beta version, (though I can't be certain of that yet), but personally I would advise against it.