Hi there,
I think it would be much more intuitive if the arrow that indicates if a node has children in the content tree were always visible instead of just on mouse over. I find myself constantly having to mouse over the tree to see if there are child nodes for an item. There's no space savings by having them hidden by default so I don't see why this type of visual indicator should be a "hide and seek" option. Obviously not critical but I think it would be a great improvement. If you feel the need to do something "cool" on mouse over, how about displaying the number of children the item has, or it's unique node id, that would be something that would make more sense to have hidden and then show on mouse over.
Related, since I always (and I think everyone does) adds a property to "hide from navigation" it would be nice if this was built in and a visual appearance to hidden nodes could be built into the tree. Unpublished items are light grey, maybe hidden could be a color or grey and italic?