As in other object-oriented architectures, the resource brokers are the key, and like other vBNS applications, much of the work has gone into the graphics. Those applications had to be specifically routed and bandwidth allocated. In TCP, the server has to repeat everything to everyone, so you end up with bandwidth consumption that is the square of the number of users. The nodes must do their own tracking of who is sharing the application with them. Data is flexible and independent.
Resources can assign themselves to tasks dynamically.
However, at least for now, multicast doesn't work well on WANs. More research needs to get done on this topic. It should start with finding better ways for the component parts of an application to measure their needed through-put, then locate the channels to peers and resources they need, and then allocate bandwidth and routes. Determining these rates and securing channels of service seems to be the biggest stumbling block to multicast at this point. Again the guiding principle is that at present, most protocols respond to delay with retransmission, and therefore, extend any inefficiency.