It would be great if there was the ability to add rules to lifecycle and revision email notifications. Currently, it's kind of all or nothing. But over-notifying people reduces the effectiveness of the notifications. There are many file properties that could help to direct email notifications to the relevant parties, so they only receive notifications when they're actually relevant to them.
For example:
Often there are people that only need to be notified of an initial release, but not subsequent releases. Or perhaps someone might only (or never) need emails notifications regarding files created by a certain user. Or maybe a project manager only needs notifications for files pertaining to their projects.
I realize adding/modifying lifecycle schemes could achieve some of the desired result, but really that's a limited and impractical solution.