Does anybody know why user_nicename isn't editable from the backend? As this is the value used to create author archives it seems like the kind of thing that you'd want to change. Right now, user_nicename is the same as the user's login name which carries some security risks first off, but people can have usernames that aren't exactly the kind of thing they want to show off. It is also odd to me that there is a setting for 'display name publicly as' but that value isn't used (cleaned up maybe) for creating author archives.
Granted, changing the user_nicename could break links to the site but so does changing permalink structure, which is quite common and is built into the core.
I'm hoping someone can explain the logic of this to me before I start jacking with things :)