Re: And who told you I want to be measured?
I'm just wondering if the chainsaw will have an IPv6 address...
As others have said, there seems no rational reason why a domestic - or indeed a commercial - firewall can't be v6 on the outside and NAT v4 on the inside. There seems to my admittedly self-centred privacy-minded viewpoint exactly no advantages to v6 end-to-endness other than endpoint availability - which is a largely solved problem by NAT as far as I can see.
One might even postulate a v4 DMZ and a v6 DMZ sticking out of the same box, for those amazingly rare occasions when we might want to run an internet facing service.