As DOD sees it, IPv6 will enable:
* Vast IP address space: 3.4 times 10 to the thirty-eighth power, or trillions of addresses per war-fighter
* Ubiquitous, scalable networking
* Globally routed addresses
* 128-bit headers with 64 bits for a network identification and 64 bits for a host ID
* Quality-of-service assurance across networks
* Easier multicasting to ad hoc groupings of personnel
* End-to-end security instead of dependence on protection at either end.
As I understand that Europe is way ahead of us in IPv6 implementation.