My vote is:

5. True bed levelling using 2, 3 or possibly 4 independently-driven Z motors and a Z probe.
6. Automatic advance of changes in the colour mix when using a mixing hot end. See deckingman's blog.
7. Support for PanelOne 20x4 text displays, or possibly 12864 mono graphics displays.
8. Ability to update PanelDue firmware via the web interface.
9. Ability to control an electronics cooling fan thermostatically based on CPU temperature and driver overheat warning.

Thanks for all you do for the community!