Our client would really like to be able to see the differences between two saved versions of a project, similar to a differential deployment report. There have been a number of other requests for functionality like this:
Multiple environment transfer + version totes (request for version saves to show differences listed in the comments)
This feature would go a long way towards providing transparency in the development process, which would in turn make multiple developer development easier to do. I think that level of transparency would also help non-BI experts gain trust in the tool.