Frankly, the ISPs likely to be tracking this list aren't the people holding back there. To pick on one that is fairly public, Verizon Wireline is running dual stack for at least its FIOS customers, and also deploying CGN, and being pretty up front about the impacts of CGN. Verizon Wireless, if I understand the statistics available, is estimated to have about 1/4 of its client handsets accessing Google/Yahoo/Facebook using IPv6.
http://www.verizon.com/support/residential/internet/highspeedinternet/networ... http://www22.verizon.com/Support/Residential/Internet/HighSpeed/General+Supp... http://www.worldipv6launch.org/measurements/
As an iPhone 5 user on VZW, I can say that they have done a really good job of deploying IPv6 on both 3GPP and LTE networks. My phone runs dual-stack everywhere I'm not roaming so far. Performance over IPv6 has been at least as good as performance over IPv4. While I'm not a huge VZW fan, they really have done this well and other carriers should look to them as a model for IPv6 deployment on cellular. The one unfortunate aspect is that if you are on an IPv4-only WiFi network, you will be unable to access any IPv6 sites via the carrier network and they will, instead, fail. For the moment, while there are not many IPv6-only websites, this is probably not a significant drawback. It's probably intended as a workaround for the "IPv6 Unexpected Data Bill" problem.
Where we're having trouble is in enterprise and residential deployments. Enterprise tends to view the address space run-out as Somebody Else's Problem - behind their NATs, they generally have enough address space to work with. On the residential side, the X-Box is still IPv4-only, Skype is still IPv4-only, the vast majority of residential gateways used by broadband subscribers are IPv4-only.
"We have enough address space" doesn't really take into account the fact that you probably aren't on the internet only to talk to yourself. If you want the users behind your NAT to be able to talk to the InterNET and not just the IPv4 InterNAT, then you're going to need to give them some form of IPv6 capability. The residential side is a problem which I believe will solve itself relatively quickly over the next 5-7 years. The cost of maintaining residential IPv4 service beyond that point (indeed, even to that point) is going to result in costs per subscriber that exceed current billing rates. Just to break even, most providers will have to convince their subscribers to pay approximately double what they currently pay while accepting progressively more degraded IPv4 service. Indeed, there are some models emerging that show that the cost of lost customers by switching residential to IPv6-only is likely less than the cost of maintaining customers on IPv4.
Some broadband ISPs are taking steps toward a managed service offering, by selling their customers a replacement router. If the router is IPv6-capable, that helps.
This is becoming more popular. Other ISPs are also specifying IPv6-compatible equipment that their customers can upgrade to.
If we really want to help the cause, I suspect that focusing attention on enterprise, and finding ways to convince them that address shortages are also their problem, will help the most.
Actually, if you want to have the biggest and best impact, it's getting the rest of the Alexa 1,000 onto IPv6. Eyeball and Enterprise conversion will happen soon enough out of necessity. However, if content is still not available on IPv6 at that point, it will drive strange contortions to attempt to keep IPv4 on progressively more complex and delicate forms of life support. If the content is all available on IPv6, then it will be mostly a non-event to start turning up IPv6-only end-users. Owen