Nuke to Disqus

Creates an xml file of existing comments
Tested on RavenNuke 2.51

Steps

Download, Open, and Edit PDO.php to match your current database credentials.
Upload to public_html folder and run in browser.
Using ftp, download exported.xml.
Delete PDO.php.
Use the Generic (WXR) option on the Disqus import to upload exported.xml.

Notes

Requires PDO extension for PHP. Mysql version soon I guess.
You can use http://validator.w3.org/ to validate.
You can check the percentage of your import status at http://import.disqus.com/.