The current username system in Next Gen forces the email address to be the username. This means that a single user (single email address) can only have one user ID. This is a problem as clients would like for a single user to be able to create multiple user ID's. FOR EXAMPLE: A single user might want to have a Admin user ID and a normal user ID so that he can check and see what a "normal user" see's. Or he might want to be able to create a shared User ID for QA purposes.