The problem with this scheme is that it's only aggregatable if there's some POP that lots of carriers connect to in the proper geographic areas. What is the carriers' incentive to show up -- peer? -- at such points, rather than following today's practices?
Leaving aside the specifics of any particular geopgraphic addressing scheme for the moment... If we adopt a geographic addressing scheme for a part of the IPv6 space we are really saying that we expect a part of the IPv6 network topology to be geographically based. While it is convenient to think og geographical divisions in terms of boundaries, in real world networks the geographical divisions are defined by peering points which the real world refers to as "major cities". So if we do adopt a geographic addressing scheme it makes no sense at all for the RIRs to allocate these addresses to entities that happen to be inside a specific geographic boundary. However, it makes perfect sense to allocate these geographic addresses to an entity who is peering at one or more of the peering points within a geographic boundary. This doesn't mean that everybody at the peering point gets geographic addresses but it does mean that organizations who have hierarchical networks with geographically delineated subdivisions can get geographically aggregatable space. For example, let's assume that one of the geographical divisions is the Romance countries. Outside of these countries the geographical address space for this region would consume exactly one routing table slot, no more. Everyone would route the traffic to the nearest network (using non-geographical addresses) which peers at one of the peering points in Paris, Madrid, Lisbon, Milan, Toulouse, etc. The global routing table would be smaller because networks which do not need detailed global visibility will not be using normal PI addresses. Geographic addressing will only work if non-geographic addressing also exists and if the geographic divisions are neither to small nor too large. RIR boundaries are too large. Most national boundaries are too small. With IPv6, routing table size grows 4 times due to the 128 bit addresses. With IPv6 routing table size shrinks because most ASes only need one /32 route. With IPv6 routing table size explodes because most businesses want to multihome. With IPv6 and geographical addressing, routing table size shrinks because most multihomed businesses only need global visibility of their routes within a larger geographical aggregate. --Michael Dillon