What sort of enhanced user experience do you see this providing? Automated change summaries?
- Robustness of versioning. Certain types of errors will become extinct. For example, refactoring will update a variable in all 10 places instead of 9/10.
- VCS can take on tasks of an integration server. The VCS now will be able to make sure that your project "compiles" before accepting a commit.
The real motivation behind this would be to make branch management easier, since the VCS has now more information.