On The Importance of Wildcard Sub-Domains and 'default_server'

I am a fan of Nginx, both as a reverse-proxy and a webserver. It is generally easy to configure, maintain, and use. In additon, it provides better performance (in some applications) and lower memory and CPU usage (in all applications), than Apache HTTPD. However, setting up a wildcard sub-domain for every domain is important to keep 'odd' redirect behavior to a minimum.