To add to the long standing wish to be able to tag families in legend views it would also be very useful to be able to apply filter overwrites.
That would save us quite a bit of time for Slab/ Wall setdown plans.
Also you would get the piece of mind that the legend colours and plan colours do always match up as long as the same view template has been assigned.
Currently having to do the phasing workaround is a nuisance:
http://forums.autodesk.com/t5/revit-architecture-forum/filters-and-visibility-overrides-for-legends/...