If you haven't already, now is the time to start to determine your strategy for IPv6 Internet connectivity. You should understand what IPv6 capabilities your existing ISP has and know what to look for when selecting a new IPv6-capable ISP. The sooner you have this information the sooner you will be able to craft your strategy. There are several places where you can find information about how ISPs are deploying IPv6 connectivity.
I must admit that it is very difficult to switch service providers. Therefore, you may elect to try to first see if your existing upstream ISP has IPv6 capability. You should first let your account team know that you are interested in IPv6. Your ISP may be gauging their IPv6 deployment based on customer demand. If they never know that you are interested in IPv6 then they may think that it isn't a service that their customers want. You should let your provider know that having IPv6 connectivity is something that you are interested in and would like to pursue.
It is better to choose a service provider that provides dual-protocol "native" IPv6 connectivity rather than a service provider that uses tunnels. The issue is that when using a tunnel you will have another step of transitioning off the tunnel at some point when the service provider offers full dual-protocol connectivity. That will be another transition step that you would rather avoid if possible. Whether a service provider offers dual-protocol or uses tunnels at the access, this difference is also an indication of the maturity of their IPv6 service offering. If a service provider has dual-protocol connectivity in their local POP then you can feel confident that they have a large-scale roll-out of IPv6 throughout their backbone. However, if a service provider is backhauling your IPv6 traffic through a tunnel to a single router in their environment that has IPv6 connectivity then it is likely that they don't yet have a robust offering.
IPv6 connectivity shouldn't necessarily cost you more money. Most ISPs don't charge any additional fees for IPv6 connectivity. They realize that every bit sent over IPv6 is a bit that is not being sent using IPv4. Therefore, your traffic volumes aren't going to increase significantly just because you are using both IP versions. Because service providers haven't been able to convince customers they should spend more for IPv6 service they have also had a tougher time justifying to their management that they need to build out IPv6 backbone services. That is one reason for ISPs being a little slower to join the IPv6 bandwagon.
We have seen signs that the amount of IPv6 Internet traffic in increasing although it pales in comparison to the amount of IPv4 traffic on the Internet. It is also apparent that the Internet default-free IPv6 routing table is growing. Just about a year ago it was about 1000 routes but today it is over 2000 routes. This is news that IPv6 implementations are happening and the first early-adopters of IPv6 are starting to join the party. Geoff Huston's CIDR Report for IPv6 shows the growth of the IPv6 routing table.
As you are comparing service providers you may be curious about their upstream IPv6 Internet connectivity. If you wanted to see what IPv6 adjacencies your service provider has you can use the IPv6 CIDR report and query that particular AS to see how well connected it is. For example, this link shows Level(3)'s upstream and downstream adjacencies.
When choosing an IPv6 ISP you can also consult the IPv6 Internet BGP Weathermap. This report shows how many prefixes are advertized by the providers. You can see that Hurricane Electric and NTT are significant players in the IPv6 Internet connectivity business.
SixXS also has a page that shows AS numbers of the larger IPv6 service providers. This page breaks up the playing field into global, intercontinental, and regional providers offering native and tunneled service.
You can also look at what Network Access Points (NAPs) have IPv6 peering and then you can ask the service provider where they connect to. In North America there are a few peering points that are IPv6-capable. Here is a list that I have compiled.
PAIX (Switch and Data): 6 locations nationwide
MCI MAE: WashDC, San Jose, Chicago, Dallas, Frankfurt, Paris
Equinix: Chicago, Dallas, Los Angeles, New York, Silicon Valley, Washington, DC
LAIIX: Los Angeles
NY6IX (Big Apple): New York
S-IX: NTT San Jose
Telx (TIE): Phoenix, Atlanta, Dallas, New York
6TAP: Chicago (Canarie, Viagenie, ESNet)
6iix: Telehouse - NY, LA, Santa Clara
STAR TAP: Chicago
If you are a higher-education organization you will have other options for IPv6 connectivity. There may be a regional backbone in your area or you may have Internet2 connectivity. There are also other Abilene/Internet2 or NLR peering points including: NGIX East is located at University of Maryland at College Park (UMCP), NGIX West - Moffett Field, CA - ARO, and StartLight located at Northwestern University. You can simply ask other universities in your area and they should be able to get you in contact with folks who can help you get IPv6 Internet connectivity.
Don't delay in asking your service provider if they have IPv6 connectivity. The sooner they hear from their customers that this is on your mind the sooner they will step up their efforts to deploy IPv6 within their networks. If your current provider is not moving rapidly then hopefully these reports will help you select an ISP that offers native IPv6 connectivity and has a robust IPv6 offering with lots of good IPv6 backbone peering.
If you know of any ISPs in North America that are offering dual-protocol (no tunnels) IPv6 Internet connectivity, then please share that info. Also, if I missed any IPv6-capable North America NAPs let us know that I excluded you from the list above.