The User login hasn't really been expanded on to incorporate many features, this is something you yourself can add to in order to support features you want to offer your visitors. Though if you give Editor status to one of your users they can get access to maintain.cgi through user.cgi which means you can delegate link maintenance tasks to others through your site.
Though user.cgi has thouasands of applications waiting to be written! It's basically whatever modifications you think will be of use to your registered visitors.