said by InTheKnow:Well actually the set top boxes have a modem built into them which up until now has been inactive. This modem will be activated for the new guide to work.
But that has nothing to do with IPTV, and that doesn't mean that boxes haven't been communicating over IP before they switched to using DSG.
DSG for the return channel is more of a layer 2 change than a layer 3 change.