Michael it would be nice if the Hide button could be moved to the Select Tab. I find myself selecting items, then desiring to hide everything else to work on it. So it's select, invert selection, back to the edit tab, then hide.

Another possibility would be a button to 'Hide Unselected'.

I also find myself toggling through the Hide states quite a bit. One click hides some stuff, a second click reverses that state (hidden objects are shown, show objects are hidden). Another click shows everything.

How about a Show All button. I know you don't want the Interface getting cluttered. Perhaps a Modifier? Hold Alt and click Hide to Hide Unselected, hold Control and click Hide to Show All? Hide by itself hides the selected item and works as it does now?

Just some thoughts.