Standing back a little, I can see an argument that IPv6 would be an easier 'sell' if there were two modes of operation, one with only RAs, and one with only DHCPv6.
This +1. There are plenty of enterprises, employing actual network engineers (allegedly), who are just about getting to grips with CIDR and VLSM. They are *thinking* about reconfiguring their hosts to stop having 10.x.x.x/8 as the interface address, and letting proxy-arp on the routers worry about which subnets are which. They *might* have been convinced that an ATM cloud (or sometimes even MPLS!) has robust traffic separation, and they don't need a full mesh of leased lines any more. IPv6 is hugely scary as it is, without breaking their "hosts and host info" / "routers and routing info" silo model. Not all of the networking world runs on Internet time :( Regards, Tim.