Fred> I see a longish thread about the fact that some cable companies
Fred> apparently are desperate to charge per IP address (something one can
Fred> only do if IP addresses are in fact a scarce resource)
I think you miss the point here. The cable companies want to charge per
computer, and the only way they can do this is to count the number of IP
addresses they see. If you use NAT, they only see one. This has nothing
whatsoever to do with scarcity of addresses.
Even with IPv6, they would still want to charge by the IP address, and
people would still use NAT to save money.