"mike:As for multicast, be careful what you wish for.
About the time folks really started using multicast, the NIC vendors were dropping the (Layer2) multicast hash filters from new designs, in favor of a single "Show me every multicast frame" bit.
So better hope your CPU and OS can handle having a high-bandwidth connection in (effectively) promiscuous mode any time you enabled multicast.
(not to mention that many popular core routers fall over pretty badly with "much" mcast traffic)
that being the case, perhaps its a slight problem then , but given that IPv6 (a layer above your point)is mandated to have Multicast and more to the point its a vital function of operation, there most be a way around any such problems as regards current core routers ?.
until we get multicast switched on all the way, we can never hope to progress past tunneling it over/through the core tear1 and thats a crying shame, the ISP's use it internally inside their networks so their users should also be given the benefits.
its not like the venders cant issue a firmware update to fix any cockup's they have made in costing their top of the line premium cost kit, perhaps the if things are as back as that then the tear1 customers need to take a stand and demand updates etc.
how would ou fix this potential problem you point out mike?, (or any other interested reader?.)