In reply to Giulio.

Hey Giulio I think your idea is really cool. Have you tested Ninja Demo for plugin and core updates purpose yet? If yes I'm looking forward to having your sharing about it.

Beside Ninja Demo I know there are 2 other guys who are wpdemobuilder.com (this guy is a service with hosting on their side) and wpdemo.io (the same with Ninja Demo). Anyone here actially has been using any of these 3?

IMHO, these tools provide great solution but I think they should expand their purpose. Only help create a WordPress demo would be a waste.