* Pekka Savola:
Do you consider BMW and Google ISPs? Do you think they should be?
Both BMW and Google need stable internal adressing, independent of the ISPs they use because their life expectancy exceeds that of your average (large) ISP. If they can't get stable public addresses (globally routeable or not), they'll just use private ones (or even a completely different address allocation scheme), and NAT as necessary. This is not an ideal solution, especially if BMW and Google should ever merge, but it's better than complete dependence on an external entity which might turn into a competitor or go out of business. If you don't give real addresses to end sites, you cannot compete with NAT in most areas. This is sad because NAT does have its problems. If another IPv6 killer application surfaces (besides the large address spaces), both BMW and Google will be able to jump through almost any hoop to qualify as an ISP. That's why it's so strange not to give them real addresses in the first place.