OK, so it is Inventor Fusion re-labeled with some slightly different UI elements. The *.123d file extension... is just a new file extension for... *.dwg. Currently if you save a *.123d file and change the extension to *.dwg it opens fine in AutoCAD and probably most CAD programs that read dwg v2010.




It seems as though Autodesk is going after the sketchup market with this at least to some extent with an online content repository.




I imagine at some point once the beta is done there will be a free version with limited file import/export and a paid for version with less restrictions. Something similar to how Sketchup opperates.

The current import/export options are limited to *.123D, *.dwg *.sat, *.stp/step, *.skp, *.obj, and *.123c
I found it intesting that there is no *.3dm import/export considering the models are nurbs geometry.




Overall, being based on Fusion, it is a very good program available for free (while it lasts...) and the content repository will hopefully grow with more users (most if not all content is Autodesk created at this point).

Drawbacks:
-Slight learning curve for marking/radial menu.
-Program is slow, really slow sometimes, especially compared to MoI3D.
-It's Autodesk, so I expect at some point a squeeze for money (nothing wrong with that, people should be paid for their work), but don't expect it to be completly free forever.
-What's up with the hard-to-make-out faces on the viewcube? What is more straight-forward than "Top, Bottom, Left, Right, Front, Back?"

One last observation: models are printable. I have not tried this out yet, and am not sure if I will, but I have seen the request here several times for print capabilities.

Hope you enjoyed my quick review.