Do you really think that today's allocations are going to be in use (unchanged) when people are building homes out of IPv6-addressed nanobots, or when people are trying to firewall the fridge from the TV remote, etc.? I certainly hope not- but then again I never thought IPv4 would be around
this long either.
I understand trying to plan for the future, but if someone is setting all this stuff up, getting a new (and larger) IPv6 block from their ISP is going to be the easiest part in the process. You're right of course.
Again, why the hang-up on 8 bit boundaries? Why not /52 or /60? /60 is not much bigger than /64, but /52 gives an end-site 16 times as many subnets as /56 while giving the ISP 16 times as many blocks as /48. Because byte alignment makes for shortcuts in routing softare/hardware allowing higher speeds? Because ARIN says so? :)
-Don