I just noticed the same thing. Is there a secondary way to verify that the root user has indeed been disabled? I still see an entry for "root" in my /etc/passwd file and under System Administrator in the Open Directory listing.The update also appears to disable the root user even in cases where you had changed its password.
Of course I have no idea if those entries existed two days ago, but back then I didn't feel I needed to check because it was supposed to be safely disabled...