Sure.
In the meantime, for the more savvy users, this functionality is already available in lua, so it is possible to create your own using the "Command" action.
Drag the "Command" action out to a macro that you're editing or onto the hotbar and when the prompt appears, type in:
script BroadcastEvent( SystemData.Events.LOG_OUT )
When you're done, press the Okay button to save it and you got your very own Log Out button!
If you want to assign a key to it, right-click the macro or the slot in the hotbar and select "Assign Hotkey".