I heard a rumour that there are small dish systems now, that can talk two ways. Why would a phone line be needed?

That rumor is true, it's called StarBand, and it's an internet service. But the normal dishs can't transmit anything back. My DishPlayer has never called home for a single thing, since I also order all PPV via the net. And even if I had a dish that could transmit, the Dishplayer dosen't know how, as well as the DishPlayer would never be hooked to the transmitter, that goes to the modem.