> > Getting everyone using routers with IPv6 support is the tricky part. But that's required no matter what!
> Well, yeah. If the plan to have v4 embedded into v6 was followed, this would have been around years ago. And you wouldn't even know you had it.
So why would anyone have added support for an IPv4 "long address" option which wasn't even being used by anyone? They wouldn't have, any more than they added IPv6 support. Both things are equivalent: addition of a new feature to your software that none of your customers are going to actually use.
My router could have added IPv6 support 10 years ago, too, without me knowing it. But it didn't.
Cable modems didn't get IPv6 support until DOCSIS 3.0, which only *just* started showing up in new devices. It looks like they've also released an addendum to DOCSIS 2.0 to allow older hardware to add IPv6 support -- in November 2010. So *maybe* firmware upgrades for older devices might add IPv6 support in the future (but I'm not holding my breath)...