One other advantage of a flutterwumper as described is that nothing prevents multiple active tools. Except for some tool sized area at the center of rotation two tools would not interfere with each other.
One reason I like that is I've really been investigating using metal powders.
Some of you have seen in Make a blurb on printing in stainless steel http://www.shapeways.com/themes/stainless_steel_3dprinting_gallery
. Now while using the tool to control Z prevents all powder based printing, it is still possible to extrude metal powder. Think about forming electrical paths through the model as it is being built.