Tony Ballardie presented work on multicast BGP. This is a protocol for defining policies for potential multicast traffic flows. This work aims to reach consensus about what is needed in BGP for the purpose of multicast, then pass on any proposals to IDR for eventual inclusion in BGPv4. This is being done within the framework of the BGPv4 multiprotocol framework (draft-bates-bgp4-multiprotocol-03). The changes since the Memphis IETF are said to be relatively small. An internet draft describing this work is in preparation.
Steve Deering suggested that this is not sufficiently general: it should be possible to derive some extensions to BGPv4 which can model both multicast (including tunnels), and several other features (eg: 6bone tunnels).