here's a way to list dns records with powershell going through wmi. keep in mind the dns class does not appear to support wildcards. :(
get-wmiobject -ComputerName servername -Namespace root\microsoftDNS -Class MicrosoftDNS_ResourceRecord -Filter "domainname='mydomain'" | select textrepresentation
i haven't figured out how to loop through subdomains and dump them out yet. :/ it's a start. hopefully you guys have something better you can share.