reply to swintec
said by swintec:I think you are looking at this the wrong way. Users don't care that v6 brings PMTUD which will allow us to use jumbo frames across the internet. They don't care about openness and end-to-end connectivity of the internet.
Okay and why is that? Why does a meaningful (read: significant) amount of residential users (my and your neighbors, families and friends) need IPv6? Why should an ISP rush this "feature" out to its residential customer base over something that markets and sells better like speed upgrades and TV features?
The average (not you or I) internet user just wants things to work.
We need to look what will fail if a user does not have IPv6:
1. P2P File transfers via many chat programs (including irc and jabber). User has a v6 address, sends to v4 user.
2. Breakage due to carrier grade NAT. 2013 is going to be the year of IPv6. 2014 is the year of CGN. Geoff Huston has some good stats on why Teredo is so fail. Most of it has to do with instances where there are multiple layers of NATs.
3. Inability to access websites. There are IPv6 only sites out there already. As the price of IPv4 increases, there will be an increase of IPv6 only sites. (eg. try and get to »bin6.it , it'll work if you have teredo). Think a person who gets a $15 VPS will pay $10/mo for an IPv4 address?