ConfigMgr 2012 has been built with the user in mind. The Software Center, installed on all clients, provides an interface for the user to manage installation of software that has been made available to them and to view software that has been installed by ConfigMgr.
While this is fairly basic user self-service, 1E Shopping provides a much richer experience with configurable approval workflow, support for system as well as user based deployments, optional restriction of deployment if insufficient licenses exist, integration with other Service Desk systems and the ability for users to rent applications for a period of time.
The Software Center can also give the user control over the ConfigMgr actions that are likely to impact them most. For example, a user can define their working day and software deployments and updates can be configured to respect these and deploy outside of these hours.