MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
I imported it into SketchUp and deleted as many of the faces that were inside as I could be bothered, then put it thru Netfabb cloud service to repair, then manually fixed up some of the missing bits that the repair left over in SketchUp. Totally time consuming and probably not the right way to do it (and not even a particularly good result), but I don't know of any better way. :D