Ernie - the new dish has four outputs so you can connect four tuners. If you need more than four you connect the four lines to the inputs of a new type of multiswitch designed for the MPEG-4 satellites - currently I think only a Zinwell 6x8 is available. The two extra multiswitch inputs are for people using additional dishes for their locals and for international stations. The multiswitch gives eight outputs. And you can stack them just like the old multiswitches.
What you can't do is diplex OTA signals onto the same lines as the sat signals, because the MPEG-4 signals use frequencies in the same band as the OTA signals.