Summary: Has enough positions to pass.
I agree with Adam's comment about the parenthetical phrasing in the abstract. I see the intent for text in square brackets to be removed. Did I miss instructions to the RFC Editor to that effect? Most likely they will figure it out, but explicit instructions would be better.
This seems like a good change; the description is well written and easy to understand; and the logic seems sounds and well-explained. The abstract should remove the parentheses from the second paragraph, as they form an important (as opposed to incidental) part of the description of the update.
I should ballot Discuss, so we can all tell Warren how awesome this draft is on the telechat itself. More seriously, I'm pretty sure I was Gen-ART reviewer for the RFC being updated, and this update seems very much like the right thing to do.
It would have been nice to use a AAAA record in the examples.
One smallish, unimportant editorial comment: In section 5, e.g.: "If the negative cache of the validating resolver has sufficient information to validate the query, the resolver SHOULD use NSEC, NSEC3 and wildcard records aggressively." it seems like the word "aggressive" has some meaning which was at least not clear to me. Is there a difference in negative caching and aggressive negative caching? If this word should provide any additional information on what to do could you maybe further explain?
Specially for Warren: "Awesome" :-)
I'm an author, recusing myself. But if I weren't, I'd ballot "Awesome" :-)