The Outliner shows object names in greyed-out text when they are hidden, so it conveys the show/hide state, but the show/hide state itself cannot be changed from the Outliner. It is possible to hide *node names from the Outliner node list*, but traditionally showing/hiding an object in the scene view isn't possible.
It would be cool if you could right-click on a node in Outliner and show/hide it in the actual scene view.
