Possible plugin in future?

I wonder if it is possible to in the future think of creating kind of a customer portal application plugin? I like the idea of this membership plugin, but I would need something client specific so that they could not see each other, nor could they see other client's work.

Right now, I am using Office Live to facilitate some of these file exchanges that I need. The customers each have their own user name and password. I upload files to them and can use a share button to send them a message that their work is done. But, they can not see each other. They also can not access any of the other customer folders that I have for my other clients.

I hate going outside of my company site though and, while the service is for now free and suits my needs, I would love to move this in-house if possible.

Just an idea for the future. I thought of this also with the community plugin, but customers can search for names or join shared groups. I want the ability to have communications with me, but not to ever be able to see other users or other customers in my network. And I would not mind a message board, but it would have to be between me and that specific client only and there can be no ability for anyone other than them to see the forum.

Just an idea. Maybe there is no other demand out there for this, but I figured I would pitch it.