It would be a good feature to have the Vault Client able to remove empty folders and the old versions folder when checking files in.
The working folder gets particularly cluttered if users do not browse to the folder through windows and clear the junk. It also bloats and takes up significant unnecessary space that will never be freed unless the user has good housekeeping habits.
This would have to take files like dwfs and windows thumbs files, but otherwise if it could be implemented it would be a very useful tool.