Mod this up. I've seen a lot of screwy analogies, but this one is first class. (Of course, there is the minor problem that half the world's economists seem to have completely forgotten everything the world has ever learned about macro. "Perhaps macroeconomics should be banned." —J. Bradford DeLong.)

"Or am I completely missing something that would have made this impossible?"

What you're missing is that IPv4 isn't forward compatible with any possible expansion of the address space.

Apple already did. It's called Back To My Mac (BTMM), it was introduced in Mac OS X 10.5. Application services available over BTMM must be IPv6-enabled or they don't work.

You should review I-D.ietf-behave-v6v4-framework. It sounds like you're talking about either scenario 4 "an IPv4 network to the IPv6 Internet" or scenario 6 "an IPv4 network to an IPv6 network", but I can't actually tell from your question. It matters because the latter is sorta/kinda doable with SIIT, but the former is just a bag of hurt, i.e. requires NAT-PT, which is deprecated for all the reasons listed in RFC 4966. Wikipedia has a decent page on transition mechanisms with some links to software you could try.

Owners? There are owners? When did this happen? Because I'm pretty sure that nobody is accounting their IP address allocations in their asset books. Do we have to pay taxes on their appreciation as capital gains? Windfall? Inquiring minds want to know.

Also, as for the argument about data center applications of NAT, I have another point to make:

There is a difference between A) using NAT because it's one of several available solutions to a problem with no perfect solution, and B) using NAT because it's a requirement of the network architecture.

Your data center application is an example of the latter, but my entry into this thread was on a topic that was an example of the former. We can move the goalposts, but let's be honest about why we're doing it, eh?

I totally feel your pain, but there really isn't cause to panic about privacy addresses and stateless autoconfig... if you don't want your salesmen to be using them, then set A=0 in prefix advertisements and set the DHCP server to hand out temporaries instead.

No, you're not going to be needing a NAT with IPv6 for normal mobile, residential and small-office usage scenarios.

I grow weary of explaining that A) NAT is not a firewall, B) your private addresses are every bit as routable as your public address when you're using a NAT gateway, and C) that just because you don't have a NAT in your cheap consumer grade IPv6 home router, it doesn't mean you won't have the cheap "simple security" functions that commonly associated with NAT gateways.

Instead, I will point you at the forthcoming RFC 6092 and its predecessor RFC 4864 and hope for the best.

p.s. Yes, you can get IPv4/NAT home routers that also route IPv6. I could recommend several alternatives, but that would be rude of me.

p.p.s. You may assume that the author of RFC 6092 knows full well that Joe User doesn't have a clue. That's the idea.

Prepare to be amazed by a sudden wave of IPv6-only mobile hosts behind broken and unreliable subscriber aggregating NAT64+DNS64 gateways that will start coming online just about the time your RIR's pool runs dry, which you will be very lucky indeed if it takes as long as five years to happen.

Or don't prepare. That way you can look brilliant when your boss says, "How is it possible you didn't see this coming and prepare for it?"

I talk with people from the majority of large carriers at IETF meetings fairly on a regular basis. I've yet to meet one who says different. As far as I know, no one in the operational community is complaining about IETF documents that recommend prefix delegation as the best current practice for commercial internet service. The 3GPP standards all assume prefix delegation to IPv6-capable mobile handsets.

Of course, if you have evidence to the contrary, I'd love to see it.

I was gonna explain all this here, but instead, I'll just drop this link. Suffice to say that there are a lot of contributors to "IPv6 brokenness" and older Mac OS X [especially pre-10.6.5] behaviors are only one of several ways that Internet users will have problems on World IPv6 Day.

This is bullshit. Every single ISP I know that offers IPv6 service today delegates a prefix. All the ones I know that are preparing commercial IPv6 services will be delegating prefixes. Even the tethering you're going to get from your IPv6-capable mobile phone will delegate a /64 prefix. Most residential providers will delegate at least a /56 and the ones run by SMART PEOPLE will delegate a /48 to each subscriber.

There is no need for residential. mobile and small-office subscribers to use NAT for IPv6.

The exception: dual-stack hosts, e.g. Mac OS X, Windows 7, iOS 4, Linux, FreeBSD, etc., on home networks with dual-stack gateways which comply with I-D.ietf-v6ops-cpe-router by advertising a unique-local IPv6 prefix even when there is no globally routable prefix available from their service provider.

Some of the newer, popular routers in the field are doing this today. Yours might be doing it right now, and you may not actually know it until World IPv6 Day arrives, when your access to Facebook, Yahoo! and Google will either be impaired or denied outright, depending on various geeky technical factors. The point of doing the World IPv6 Day exercise is to find out just how bad this problem is going to be.

On top of that, we have an excellent way to keep your teen-age daughter from running up the home phone bill with 900 services: an unlisted number! She won't be able to make trouble if she can only make outgoing calls.

If you don't want any host outside your house to communicate with your NAS box, then giving at a private address behind a NAT is the wrong thing to do. Every private address behind a NAT gateway is routable to exterior domains. If you assign a globally routable address to your NAS box, even a private one from RFC 1918, then you need a firewall to prevent it from communicating with hosts in exterior domains. (No, your cheap commodity NAT gateway is not a firewall.)

With IPv6, you can assign your NAS box a non-routable address because you don't need a NAT gateway as your home router.