My problem with ArcGIS products is that they are already trying to do too much. Adding more features is just going to dilute the product which I think should focus on data integration. I would prefer to see better integration with existing 3D products rather than adding more 3D features.
I agree with your comment Isabel -- the multiple 3D products just excuse ESRI form having a common 3D interface for geometry manipulation -- not just for visualisation, but serious 3D editing. The same goes for multidimensional rasters ;-)
