Robert Cringely writes about IP multicast and P2P for video distribution.
Personally, I don’t worry too much about IP multicast. If it were turned on I believe it would work, but I don’t expect it to be turned on. If the Mbone had been such a success, maybe we’d see more multicasting, but I don’t think the Mbone proved much of anything. Cisco tried like crazy in the late 1990s to promote multicast, for which it bought Precept Software and the original IPTV application just to show the world how television could be done right in an IP-centric world. Only nobody bought the concept or much Precept software. You can learn more about Precept and IPTV in the new episode of NerdTV, which is with Judy Estrin — who founded Precept then sold it to Cisco and became Cisco’s CTO for a couple years. Judy says she built Precept’s IPTV around IP Multicast not just because of its obvious efficiency, but because she had read Cisco white papers on IP Multicast and, “Sadly, I believed them.”
No, IP multicast is not THE solution to wide deployment of video content over the Internet. It is one possible part of such a solution for ISPs who choose to enable or impose it. But p2p retains the advantage of running well on networks that don’t choose to support multicast, which is to say pretty much the whole darned Internet.