There is good news for Milkshape3D owners. 3D Shell Extensions now supports MS3D file format (versions 3 and 4). Look at the shot below:

I'm testing this version now; I'll make it available when implement 2 or 3 other 3D model file formats.
If you are registered owner of CR Pack or 3D Shell Extensions or if you're planning to use full version of 3D SE in a future, please, vote for new 3D model formats for it:
http://lion-ts.com/modules.php?name=Surveys&pollID=5