its still there, root hasn't gone anywhere. try going into your System Preferences > Login > Login Window and screw around in there. you can have it so that only icons and names of the users made already appear, or you can have it so that you have two black entrys upon login, one for Username and the other for password. i have it so that it shows the users, and so that it has the Other... login enable, you can click on this and enter any login name you want. in your case, root and whatever your password is.