In our 2.1 Community release (due to be available later today), we now provide support for content launch and expiration.
At submit time, publisher can specify a launch date for their change set. After content approval, the approved changes are maintained in the reviewer's sandbox and labeled as a pending submission. In the GUI, underneath Staging, users can not only view snapshots but also now the list of changes awaiting submission. You can then publish your new message of a day and stage for delivery tomorrow morning, see that you have the message of the day staged for delivery, and at any point prior to the launch preview the future state of a website.
Please take a look at our upcoming 2.1 release.
Kevin
