http://www.appleinsider.com/articles/08 ... ction.html
NBC Universal will offer one free download from each of its top series—in standard or HD—during the next two weeks. The premiere episodes of upcoming NBC shows, such as “Knight Rider ,” “My Own Worst Enemy” and “Kath & Kim” will also be made available on iTunes a week before their broadcast premieres later in September and October, with subsequent episodes available the day after broadcast.