It would be really usefull for large assemblies to invert the current selection.
When I am working on a large assembly I sometimes want to only view a few components or sub-assemblies. This makes it much easier to see the components and make changes to them. If I could simply select the components I care about, invert selection, and then hide all those newely selected components, that would be great!
Of course if there is another route to achieve the same thing I am fine with that too.