[ppml] PIv6 for legacy holders (/w RSA + efficient use)

[Paul Vixie]

> You misunderstand.  It isn't _my_ transition strategy, it isn't even really
> a strategy (is predicting a rock will hit the ground if you drop it a
> strategy?).  I'm merely suggesting it is the most likely outcome of the
> situation we've placed ourselves in.

as i have been shown the folly of ignoring your wisdom in the past, please
elucidate.  what other outcomes were measured for likeliness, and why was
this one selected?  (without the backup data, the above statement still
seems fatalistic to me, but my mind is open.)