On the "Deployment Summary Page" it would be great to add a column to the list of metadata components added which shows for the "No Difference" items showing the source piece(s) of metadata which is causing this "No Difference" to be included.

This would dramatically help in the narrowing down of why a piece of metadata is included - especially if that piece of "No Difference" is a managed package and cannot be altered. In a large deployment, trying to identify a root cause for why a component was added is quite difficult. Simply giving a way to track back the cause will definitely help speed up the process of getting the package ready to deploy.