From AGI:
"Rome, Sep 20 - Trenitalia is about to launch a new promotional initiative called "Happy Train". As of September 19, passengers will travel all over the country for just ten euro in both first and second class on board Eurostar, Intercity Plus, Intercity, Intercity Night and Express trains. After logging on the web site www.trenitalia.com, passengers will have to select their favourite journey from a list of different offers. Then, they will buy their tickets online. Some 40,000 seats a day will be available on 65 different trains. Passengers may choose not to collect the ticket before boarding the train: in this case, they will have to provide the ticket inspectors with the journey code they were assigned online . Otherwise, they can call the telephone number 892021, and ask the operator to buy the ticket for them. The purchase includes a reserved seat. Passengers will have to use their tickets only on the selected day and train and tickets can't either be substituted or refunded."
This link is to the Trenitalia Passes available from RailEurope, but not the special mentioned above.