I am looking for GIS software that
can model office accomodation, move
around occupant groups, query,
and possibly use 3D displays of
buildings over orthophotos. Any
ideas out there as to what software
could perform this?

MapPoint could be good at modeling the building-level data with custom shapes, hyperlinks to aerial overlays, etc. The main thing MapPoint would give you is map data around the buildings to put them in perspective in relation to one another and surrounding areas. Beyond that you might look at Visio or a GIS package like MapInfo or Manifold for modeling of office space inside the buildings as that is essentially custom data. - Eric