Yes, I know there's no way to hide the top panel (http://askubuntu.com/questions/30430/autohide-for-unity-bar-and-panel).
This is a user request with a valid Use Case: - run MythTV...this is a full screen application - if you set the top panel's opacity to 0, it shows the desktop, not the MythTV window
Seems broken or mis-designed to me :-P
Please at the very least, add an auto-hide option...
unity-2d-shell, the gnome panels are fully configurable. – mateo_salta May 4 at 3:12