1. IPv4 address space is a scarce resource and it will soon be exhausted.
2. It hasn't run out already due to various efficiency improvements.
3. These are themselves limited.
4. IPv6, though, will provide abundant address space.
5. But there's no incentive to change until enough others do so to make it worthwhile.
6. Economists call this a collective action problem. Traditional solutions include legislation, market leadership, and agreements among small actors to achieve such leadership.
Let's keep in mind here, that a number of "organizations" -- the US Gov't, Japan and a few other places that get pay for things without a real market incentive are moving to support IPv6. They will in turn put more pressure on their transit providers, vendors and IP talkers to talk to them on IPv6. This may help build #5's case up. Cisco (via Linksys), Netgear and other consumer brand router manufacturers may start supporting IPv6 if the ISPs that are providing broadband start it, or the employers of these home customers (vis-a-vis the US Gov't) start making it easier to use their IPv6 VPN vs their IPv4 VPN. Content providers (as response to customer pressure) may opt to make their services available on native IPv6 if the networks that are using IPv6 have crappy IPv6-IPv4 gateways. (e.g. Video distributors, etc). Market forces are already underway here, I fail to see why so many people are so concerned. Yes, we like hierarchical allocations, they are yummy to routers. Yes, we deal with humans and some adopt much slower than others. Maybe I'm missing something, DJ