WordPress.com has launched a feature called Email Post Changes to help blogs with multiple authors collaborate better on the same posts and pages.
Nick at WordPress.com said:
More than 460,000 WordPress.com sites have multiple authors, with one site having 641 users, so we think this will be a great feature for a lot of you. We’ve been using the email notifications at Automattic for a while and hope it will be as useful for you as it has been for us. If you have an interesting usage, let us know in the comments.
Email Post Changes support document at: http://en.support.wordpress.com/email-post-changes/
The Email Post Changes plugin has been updated for self-hosted WordPress.org users.