Hmmm.... while all that makes sense to me, it seems somewhat illogical.
What if user "x" wants to have 3 DB's sharing the same user? Obviously I am not going to give him the admin user info, doesn't it make sense to have it setup like this:
Login to the user account, click "MySQL databases" choose "Create new database" and if a user is already made have a drop down that says "Use this user: domain_user" or "Create new user..."??
That way we can have both options.
What do you think?