Olsen, clearly you do not understand that the transition is already happening, and it is IPv4 that is left behind.
I understand that it is underway, my point was just that with the type of devices that are still IPv4 only, cannot be easily upgraded if at all, and are installed in sufficient numbers, you can't just force a switch to IPv6 without taking care of your customers.
For example, one German ISP ran out of IPv4 address space and had to use IPv6 for new customers. Those customers who owned game consoles (XBOX360, PS3, etc.) found that they could no longer go online, because these devices supported only IPv4 operations and the ISP's NAT was not up to the task. As far as I know even the current console generation (XBOX One, PS4, WII-U) is not entirely IPv6 compliant yet, part of which may be due to how the game server infrastructure operates, and what happens if players which use IPv4 and IPv6 need to talk to one another.
A game console is the type of device which I have in mind when it comes to make a transition from IPv4 to IPv6 easier because the manufacturer may not be particularly helpful, the device is not cheap and is not easily replaceable during the next product cycle (6-7 years for a game console?).
I do realize that ISPs and carriers are itching to get rid of IPv4, especially if their customer base is very large. A corporation such as Comcast probably has its subscribers NAT'ed several layers deep to avoid running out of public IPv4 address space. Never mind the cost, it makes the network operation unnecessarily, if not nightmarishly complex.
Here is an example of what is going on...
https://sites.google.com/site/tmoipv6/lg-mytouch
This looks like the ideal and maybe typical case for carriers: very large number of subscribers (T-Com USA has more than 50 million customers, or so), big network which spans the entire continent, and squeezing all this into a set of IPv4 address ranges is just expensive trouble waiting to happen. T-Com can make that switch rather easily, as customers can replace their gear within 1-2 phone product cycles (1-2 years, probably less).
If the customers use the phones provided by T-Com, replacing the phones that don't do well in an IPv6 environment becomes even more convenient. The customers may not even notice the cost for the phone replacement because it happens along the normal technological upgrade path (say, you keep your iPhone for two years and trade up for the new model).
