It is often desirable to avoid sending a change email to the author of the change, even if the author is subscribed to the page he just changed. Ie- I do not want to get notifications of my OWN changes.
I've made some small changes to the subscription functionality which I would suggest be made part of the core functionality. Maybe a config option to turn this on or off (at the user level?) would be desirable too.
I put my details and code here:
http://wiki.splitbrain.org/wiki:subscription
Involves minor changes to the notify(...) function and the subscriber_addresslist(...) functions in the inc/common.php file.