At this point, ISP's should make solid plans for supplying customers with both IPv4 and IPv6 connectivity, even if the IPv6 connectivity is solely for their web servers and mail gateway. The priority is not getting customers to use IPv6, it's getting their public-facing servers IPv6 reachable in addition to IPv4. Exactly.
So many people seem to be obsessed with getting the end users connected via IPv6 but there is no point in doing so until the content is reachable. The built in tunneling in Windows could be a problem so let's start by using different dns names for IPv6 enabled servers- mail.ipv6.yahoo.com or whatever. Can anyone think of a reason that a separate hostname for IPv6 services might cause problems or otherwise impact normal IPv4 users? -Don