Brief: It changed from being something remarkably daunting to being something remarkably easy– two lines were added to wp-config.php as follows:

/////20091012 - CHANGED for DOMAIN MOVE.
define('WP_SITEURL', 'http://eddiema.ca');
define('WP_HOME', 'http://eddiema.ca');
/////

– After that, the apache ‘.conf’ file got an update so that both tin.blogdns.com and eddiema.ca pointed to the same doc root.

As far as I understand, this means that legacy posts (although branded with the previous subdomain in the mySQL table) can be served up under my new domain name, while new posts will be written to the table using the new branding. This is the behaviour I was hoping for! No need to update legacy entries, and full forward compatibility.

– Great! The wiki and my ticketing system are still working!