But IP Multicast won't cut it for the current method of watching TV on the Internet "on demmand". Right now, say you want to watch last week's episode of your favorite show. If its multicast out, then anyone who starts the stream after you will have missed the beginning. Kind of a bummer for them. IP Multicast is great to stream shows on a scheduled basis. Then viewers could "tune in" at the appropriate time and catch the show, just like they do with standard TV.

Its possible that someone may devise an way for the "on-demmand" viewing model to work using the efficiency of IP multicast, but right now its not a drop in replacement to magically save bandwidth.

BTW, I am a big believer in using multicast on the Internet...