Yes and no. Technical limitations in things like in-addr name service make moving things with any boundary in the last byte very difficult, but things with any boundary before it possible (and a boundary on a byte much easier).
But there are ways to do this -now-. Folks are just not willing to do it. (Ever look at how TPC.INT works? How about NSAP in-addrs?) Look, the in-addr argument is just that.
I'm not familiar with NSAP's setup. I have looked at tpc.int, and it looks to me like they could have done it with just a largeish standard named configuration. Nothing fancy, no new technology, just a little thinking about the configuration. You'd either have to have a lot of huge manually maintained files, a hacked named, or some sort of build script and intermediate db format to do the in-addr maps for sub-C nets. Ok, I can see how you can do it (a few days work at most), but it's still a hack. Wasn't that your criticism of the buy-and-sell-blocks-of-C's fix? 8-) Has anyone tested to see if all the BGP-using hardware out there will actually deal with advertising nybbles as opposed to Cs? -george