I have the same question as this article regarding assigning User Types to users, but it seems version 10 has lost capabilities that version 9 had as there isn't even the option for the user to select their own type(?).  

We're heading towards launching Discussions as an internal knowledgebase and intend to have Moderators and Subject Matter Experts from different departments hold different user privileges so we want to be able to identify those users with User Types.  But I can't figure out how to assign a User Type to a specific user. 

Your assistance is appreciated!