Have you seen this startup? Handprint, they’ve won a rent-free premises plus @Google_Fiber for a year courtesy of @MakerBot1 board member @Brad_Feld . I think they could be a bit of a @Tinkercad crossed with @Shapeways marketplace.
http://www.prsnlz.me/industry-news/the-house-that-brad-built-3d-printing-startup-win-fiberhouse-competition/