Personally ... I think, that whole BIM marvel must one day reach its climax.
Parametric tools mimic real objects and there is no need to make them better than reality.
You can improve apps speed, interoperability, data sharing, GUI etc but virtual window will be always only symbolic representation of the real one.
Revit or any other app can't escape out of this reference frame.
vw doesn't have to be blazingly fast in the implementation of parametrics but they should do it consistently, with minimum bugs and with big portion of original ingenuity.
This whole run on BIM will softly land on flat part of the saturation curve of parametric functionality.
Just do it right
make it perfect and real ..
(original: http://youtu.be/S5SkI8zmFNw)