If you now try to find <tt>/sudo:dev.example.com:/etc/httpd/conf/httpd.conf</tte> Emacs will automatically create the SSH connection first, prompting you for your password if necessary. Then it will prompt you for your sudo password. Once this is all done you will be able to modify the buffer as necessary. Saving the buffer will do what you expect: it will update the file on the remote server.
Hops can be chained, making this feature extremely powerful.