[[ mailing-list moderator note: non-member submission ]]
Pekka,
This is why the fundamental first question in considering the
"opportunistic" tunneling is whether you consider the deployment to be
"vendor-driven" or "user-driven".
I don't understand the distinction you suggest between "vendor-driven" or
"user-driven". Vendors will supply the products that most people will use
independent of how the products are used. Most "users" don't write
specifications or write code.
Is the distinction whether the transition is driven from the middle (i.e.,
an ISP providing native IPv6) or from the edge (via automatic tunneling
where the users ISP doesn't yet support native IPv6)? Or something else?