Possibiliy to set joomla group/user permissions on categories and not only documents. In that way you can restrict a user/group of users from viewing a category on the frontend.

Maybe compatible with the upcoming ACL implementation in Joomla 1.6?

Option to enable administrators to add special fields to the Front-end document submission form such as: version #, original publication date, ISBN number and many others.

Have a search function which searches not only in descriptions, but also inside documents. Like the components PDF Indexer and Doc Indexer, but only for the documents the user is allowed to view.

Ability to have a document expiry date a download limit and perhaps the ability to have unique unguessable URL downloads with a hidden option, which are all configurable from the Document tab on Edit/New document link. An auto delete feature which can possibly delete the files after expiry too.

The unguessable URL part could be something like

http://server/index.php?option=com_docman&task=doc_downloadgid=923fa1e92c12480697ea157383f65ec0&Itemid=27

That way if you select a hidden option for the document, you could send a direct link to a person without others knowing about it

For example: Filename "Test File" and catagories "Catagory 1" and C"atagory 2", should be able to assign file to both Catagories "Catagory 1" and C"atagory 2",

Automatically track name/date and sequential version # for document. Also allow user (if configured) to go to a previous version/history

Let users upload new documents through the frontend, but only for categories they have access to.

Instead of having to use templates to style document pages, add options to allow backend user to change fonts, layout etcetera in an easy way

The ability to further protect documents by assigning individual passwords would be a great leap for my project. The user would have the option to define the password in document upload/creation. The reason is so that I may allow registered users access to a private area where only those who know passwords may view certain documents that have password protection enabled.

Allow users to collect items in a cart and then download a ZIP file.

Addition of a comments function to enable users to add comments to a particular entry, either by a build in comments system or by integration 3P joomla comment solutions or webservices like disqus or intensedebate.

I don't know if it does that already, but surlely downloads should only be counted if the file has been downloaded COMPLETELY. otherwise you get tons of hits on the counter just from bots and people who had broken connections and try again later.

Make it possible to present AND play MP3 files (or other sound files) in DOCman

Option that allows choice as to whether a Ratings Function is enabled or not for documents (much as the Content Items rating in Joomla!)

Integrate DOCman with web-based file sharing and storage services like the following:

1. box.net
2. Dropbox
3. FileShare
4. YouSendIt
5. Amazon S3
6. ...

Allow for download and uploading files to these webservices, both from frontend and backend.

Allow users to sync DOCman to their own account and have DOCman act as a gateway.

I think a good idea to use a drag-and-drop as JUpload to upload multiple pictures at once.

Add the ability to produce rss feeds for new and updated files. Allow users to subscribe and be notified on updates etc which would be very handy.

There are many of us, who would switch to Docman if it would support complete data migration from Remository. I'd love such an option in the future.
Anyone who needs this feature, please vote!

Allow user to set multiple groups or individuals in all permission dialogues ... either categories OR documents.