The maintenance bed first appeared in the Fall 2016 treasure hunt as a simple static prop that units could lie on, with the option to flip 180° so that the unit's front or back could be accessed. The full maintenance bed would be able to report the unit's status, including integrity, personality, and subsystems states, toggle diagnostics mode (similar to the old charger feature), and perform key maintenance tasks such as a factory reset, making it possible to leave domains and remove owners without sending the usual tattle messages.
Update (2017/06/26): The code for this is done, including a built-in package server that can only be accessed when lying on the table. Some model tweaks still need to be finished; we hope to have this released soon.
Update (2017/07/01): Released! There are some permissions bugs still in the controller that may affect using beds that belong to you don't know, but hopefully those will be resolved in the very-soon-upcoming 8.5 first preview release.