I'm pretty sure Don's suggestion would work. That is: in CVS you can add a watch. When something changes the user that added the watch gets an e-mail update.
The main problem is that (I think) most people log in using the anonymous CVS account. If you can set an e-mail address for the anonymous account then you could just point it at the mailing list.
Failing that you could add a user to the CVS repository for the purpose of these updates and set the e-mail address to be the mailing list. Then add a watch to the openacs4 directory and anybody subscribed to the list would get it.