Please add the ability to view diffs between particular revisions of a document.
Currently, you have to look through each revision one by one to see what changed between two particular points in time. It would be great to be able to view all of the changes that were made to a document within a particular range of revisions at once, as can be done on Wikipedia or almost any wiki-style site.
The user should be able to select two particular revisions from a document's history. The user would then be shown a diff of the document between those two revisions with all changes made in any revision between those two highlighted in the document.