For the next major release of ArcGIS for Desktop, I think it would be integral if there was a GUI designer that could be used to develop custom user interfaces for python tools. I envision this to be the next generation in python tools boxes.
The GUIs could use one of the many form designer languges like wxPython (used in the python add-ins) or Tkinter.
VBA had one good thing going for it, and that is the form designer. I would not like the forms to be linked to the map document, but rather more like the add-in system introduced at the 10.x series.