Version management of documents with the brain, currently this is manually, in fact you create another document with in fact another name (adding a version index to the attachment name). I think this should be handled by the brain itself. When you add an attachment it gets a unique id in the brain database when it is changed you can save it under the same name and the versioning is taking care by by the brain. Only the last version is visible to the outer world. But older versions are still accessible. Parameters about how much versions and how long they need to be kept could be defined in the preferences.

Doing this it would allow people to make reports on the documents they have changed in time. In fact by having a report that represents the changes on a time-line. As you know that is one of the views most people are lacking: give me a view on all documents I have been working on during the last 2 or 3 weeks or in a particular period some months ago.