From the dualstack-is-fun department...

[Martin Millnert]

On Mon, 2011-02-28 at 23:31 -0800, Cameron Byrne wrote:
> This also creates the ugly situation where customer calls help desk
> saying website x is down, support person tries to get to website x,
> and it works. Help desk says, nope "works for me" and the broken ipv6
> access or dare I say ipv4 access is broken to the none-HE user but
> works for the HE user. If the none he-user cannot easily convince
> others that there is a problem, that is bad. 

Cameron, the below seems ~obvious to me in the scenario you describe:
"[...]
HD: What browser are you using?
Cust: X
HD: Well I am using Y v. Z [with HE implementation], try installing Y.
You will need this one [to continue the debugging].
[...]"

A "possibility" help-desk side, however rough, "un-scalable" (ie,
ISP-expensive) and sub-optimal. Given the complete problem scope we are
facing I'm not sure what is going to be worse though:
  13min latencies, bad customer experience and multiple support calls,
vs. having a procedure to track down the root cause that HE/disabling
ipv6 fixes. Support desks will need updated flow charts - "boo hoo" :)
("I encourage all my competitors to give crappy customer support...")
  And should this become widespread enough, eventually news media will
start say that you have to use "Y version >= Z" to use the Internet... 

The above doesn't strike me entirely bad in itself. 
  Pain's going to hit somewhere for sure and there is no realistic
one-stop solution for all problems, so we have to continue to expand the
band-aid kit. 

HE connection success/fail statistics / logging and opt-in reporting
somewhere would certainly be a nice addition as well (name the button
"Make the Internet better..." or so :) )

Regards,
Martin