I read once about someone using AutoCAD to make parametric 3-D wireframes and then using them in Rhino, sounded completely insane and in no way better than just using SolidWorks (or other).
The one thing this new Alias Speedform has that I know Power Surfacing does not have for SolidWorks and I don’t think (though not sure, it might have now) TSplines for Rhino does not have is to be able to make a single surface into a Nurbs surface that can be manipulated with TSplines. I think when Parametric modellers get this (it seems Creo does from a previous post) than pure Nurbs and subdivision modellers will be unnecessary so I would recommend going for SolidWorks personally, and Creo on the side.