It would be good to be able to exclude commits made by a given user from generating commit mails.
My immediate need for this is because I subscribed to commit mails using my openid. So I don't get commit mails for changes I make over the web, using that id. But, if I do a svn commit, that's from a "different" user, so a commit mail is sent to me. This particular case could be treated as ikiwiki needing some way to link together openids and other accounts, which could also be good, but I think the general case of not wanting to see changes some other user makes is reasonable.
Extending pagespecs for commit mails would be a nice approach. Then I could subscribe to:
* and !SandBox and !user(joey)
Insert standard argument about how wonderfly flexible this is. 