Just got this in from the folks at MachStudio Pro, but if you head on over to the StudioGPU Downloads page you’ll see a few new free export plugins for Rhino 4 and SketchUp Pro7. These export native MachStudio GXB formats, that can then be manipulated within MachStudio Pro as native objects.
The exporters can be downloaded at their website, http://studiogpu.com/downloads/, and are free!