While I understand and accept your argument here, whether we'd ever run out of address space imho has nothing to do with /48's. How many /32's have we got to play with ( 536870912 per /3 by my calculations) OK, that's still a big number. But if we allow everyone who wants to multihome a /32, there is the possibility that we could run out - not in the near future that's for sure.
Many companies are still discovering how/if they can use the internet. As more and more uses for the 'net are thought up, companies are going to become more and more reliant on the 'net to the point where they will/may struggle to function without it - somewhere around that point, all companies will need to have a permanent connection and in my mind a permanent connection means multihoming.
How many companies are there in this world ? Thus how many potential multihomers have we got ? - more than the number of /32's available, I doubt it (I don't think there are 4 billion companies). We're a along way off home users multihoming, so perhaps we'll never run out of /32's. But I for one would not like to bet on it.
Shared reluctancy to bet on it, as a basis of building policy at least. Cheers, mh (as6453)
Jon