I, Cringely . The Pulpit . The $7 TV Network | PBS

Always interesting Cringely -- read the article for a snapshot of Neokast 

Multicasting hasn't broadly succeeded before now primarily because it places a large burden on the routers, which are responsible for caching and retransmitting video. Multicasting is generally turned off in routers to save bandwidth and keep the network running as fast as possible. Cisco wanted to turn multicasting on for IPTV specifically so the routers would slow down and have to be replaced. With Cisco it always comes down to routers and how to get people to buy new ones. That's evident in Cisco's purchase this week of WebEx, where we can expect Cisco to strongly push video services on those two million WebEx customers, straining the system and forcing hardware upgrades. It's not about Microsoft; it's about the routers.

Source: I, Cringely . The Pulpit . The $7 TV Network | PBS