I’ve been working on adding email notifications to Content Audit. It now has options to automatically mark things outdated after a configurable time period — 3 months, a year, whatever. You can then email the assigned content owner or the original author a list of all their outdated content.
I’d like to have a few more people test this before I release the upgrade. If you’re willing to bombard yourself with email, download the beta zip and try it out.
There is a quirk in the way WordPress schedules events. As a result, when you update your notification options, the emails will be sent immediately and then scheduled for the future based on the interval you set. Therefore, I highly recommend that you a) use this on a test installation first, and b) make yourself the owner or author of all the audited content before trying out the email notification options. Of course, if you do that using Bulk Edit, the content will be updated with today’s date and it won’t be outdated anymore! Use a query on your database instead. If your user ID is 13, it would be:
UPDATE wp_posts SET post_author=13;
This version also fixes a couple of bugs (including the annoying “line 79” error) and is, at the moment, compatible with WordPress 3.1. Let me know how it works for you.