Distributed design is discussed in better detail in the below blog post.
http://forums.autodesk.com/t5/fusion-360-product-roadmap/distributed-design-in-fusion-360/ba-p/55495...
The easy explanation is that distributed design introduces design referencing, the ability for one design to update based upon another, separate design. Now when you use the "Insert into Current Design" command, to insert one design into another:

You'll note that there is a chain icon next to the item's name in the browser:

When this is present, the local translators are disabled (currently). For now, there are two work-around solutions:
- Use the Break Link command to break any of the cross-design references located in the design. All of the "chain" icons have to be removed from the model browser. After doing this, you will find that the Export command works. Note that after exporting the file, you can use Undo (CTRL + Z or Command + Z) to undo the Break Link command.
- Use the Autodesk 360 cloud translator instead of the local translator. This will require you to open the Project Dashboard in the web browser



I should note that it looks like a fix is coming for this issue in the next update. This fix will address the ability to use the local translators with one exception. The archive file format *.F3D, will not support X-REF's and will be disabled for distributed designs.
I hope this helps to clarify some quirks. Let me know if anything is unclear or if you have any questions.
Thanks,
Nathan Chandler
Principal Specialist