I often like to see the effect of edits on the votes of a post. This can be useful when reviewing, but it can also be an interesting statistic. Besides it is cool to see the effect of your edit on a below average post.
A way to do this, is to is to preserve the amount of up and downvotes of a revision.
Example a clueless user asked a bad question, getting two downvotes. Another user, edited the post making it much better. Now the question got 3 upvotes. (See also the example below). Each revision now shows the amount of votes it has, the moment a new revision is added. The last revision shows the current status.
I can imagine, it takes some heavy queries, so a restriction for users with 5000+ reputation would be wise.
And ofcourse this can be expanded to the number of answers, and (for questions) number of favorites.