Custom installer / updater

I was wondering if it is possible for an organisation to create a custom installer / updater which instead of getting the list of applications and updates from your site, it uses its own server to distribute the installation packages.

Reason for asking is that in big organisations what staff can install is often restricted and controlled. And even once an application has been approved for installation, keeping it up to date is a nightmare as each application has its own way of doing this.

It would be great if an IT department could provide people with a portable app platform and makes a server available where approved applications are kept. This way, the IT department can stay in control of what staff can install and make full use of your great system for updating and installing apps.