Why all the fuss over Apple tv? Well for one Apple will be offering content the same way that it is offered in their digital store.
Clients will be able to purchase whatever content they want, whenever they want. If you feel like watching True Blood, Game of Thrones or Dallas, no problem, just click and watch. Unlike cable where you haev to wait for the allocated time slot or set your recorder to record and watch the show at a later time.
Will Apple TV replace cable? probably not, but it should offer great convenience.