So I see that .3MF is the new file format that MS came up with . They are working with other companies in the field to refine it further.
Looks like a way to get this OS a step-up in the 3d printing field.
here is the official site: http://www.3mf.io/
http://www.3ders.org/articles/20150501-microsoft-announces-new-3mf-3d-printing-file-format-launches-3mf-consortium.html