This tiny module provides a new tab which allows a user to post a new revision of the body of a node only, this is, she will only be able to edit the body of the node. No other part of the node form is shown, besides the title for information only (no editable). In order to have this functionality without having to give 'administer nodes' permission to the user, this module needs a patch for the node.module. This patch creates new permissions on revisions and nodes (delete).
Don't use this module if you are not comfortable with a patched Drupal ;-) Hopefully some of this new revision permissions will get into core, eventually (!?)