It's not going to be temporary and it's not going to be 'a few' - also I shudder to think what the 1500-ish LIRs who already have a /32 allocation will do based on this.
6RD costs money. There will not be very many ISPs doing 6RD and the 1500 LIRs are not going to derail their existing deployment efforts. It costs money to implement 6RD, it costs money to operate 6RD and it costs money to remove/replace 6RD with native IPv6. The organizations that will use 6RD are the ones who get a financial benefit from delaying spending on native IPv6. Perhaps they have older routers in their network that are not yet end-of-life. Or perhaps their systems support tools are coded in unreadable PERL code by people who left the company 10 years ago. 6RD is not a magic bullet, just one more option to consider for migrating the complex path between today's IPv4 Internet and the native IPv6 Internet of 2015. And as others have pointed out, we can afford to give every RIPE LIR a /24 if we have to. There is no reason to panic and this is not a slippery slope situation since real-world considerations limit the number of LIRs who would use 6RD.
Probably get the extra /24 and not return the /32 because there's already some stuff in there that can't be migrated because it's too expensive and will hurt IPv6 deployment. The same arguments supporting 6RD right now.
This is not a question of arguments. The 1500 LIRs who already have IPv6 allocations are already running IPv6 services. Many of them have customers using their IPv6 services already. It is possible that some of them might decide to use 6RD for their broadband because of complex issues with the broadband access network, but given that leased line and data centre services are generally more profitable, or tied to more profitable customer contracts, I don't see why anyone would want to migrate away from an existing /32 allocation.
The good news is, this will double the IPv6 routing table in size. The bad news is, this will double the IPv6 routing table in size.
Not very relevant. The IPv6 routing table is not that big right now, the addressing architecture tends to limit growth of this table and vendors have already demonstrated the ability to handle much bigger routing tables than today. --Michael Dillon