Conservation is not an issue regarding IPv6.
...within an address block, this is true. However, what is being talked about here is "globally routeable chunks of addresses", and there conservation *is* an issue, since nothing really changes with respect to routing with IPv6 compared to IPv4.
It is best to clarify what resource we want to conserve. I don't think there is any need to conserve IPv4 addresses any more. Exponential growth is a think of the past and we have enough IPv4 addresses to last 10 to 20 years. We also have a replacement protocol, IPv6, that is already commercially deployed in Asia and in Europe. However, we might still want to conserve the number of entries in the global routing table because of the impact on router memory, router CPU and the time required to reload a full view of the Internet when a router is restarted. If we refuse to give DENIC a /24 from the recovered "Class C" swamp space we would be saving a small amount of IPv4 address space but we might not save any global routing table entries... --Michael Dillon