This raises another critique of the argument to sequence DNSSEC first, then addt'l TLDs, IPv6, etc.  If we're only doing a 100 TLDs/year then the "big jump" becomes a non-factor for a while - so we shouldn't rush signing the root.

Yes, I learned in questioning Lars that the "big jump" would only happen if we were talking 100,000 - 1 million TLDs, not 100.
And I learned the lines on his graph were simply made up to illustrate a point - they were not scientific products of the simulation.

Or, even if we sign the root, we can still add 500 - 1,000 TLDs, no worries.
--MM