Steinberg has published details about the new VST Transit feature of Cubase Pro 8.5.

Transit is a cloud-based project sharing system.
It includes the simplified transfer of all the media files and synchronisation of the projects state between members invited to the project.  Charged based on data transfer and online storage usage: free basic accounts for now, premium accounts by mid-January.

This looks like a very streamlined user experience for collaborating.

All the details are in the video. See also Cubase’s features page.