I am the designated DNS Directorate reviewer for draft-ietf-dnsop-zoneversion.
This is the forth review I am doing - in my last reviews on the -08 and -09 versions I 
came to the conclusion that the document is ready for publication. 

The draft is going to be published as Informational RFC. The document is well 
written and defines an EDNS option which can be used for debugging purposes.

Again, there were only a few minor changes (being raised during WGLC) to make 
the document more clear and  readable compared to the -09 version. In addition 
some of the references were changed (removed).

Overall I think the document is ready for publication.