Unfortunately, this still isn't a great solution. We have a few hundred macs where I work, running software update once a week (they are staggered), by way of a cron job. Seems that if for some reason a mac is rebooted during this job, there is a good chance the OS will get completely hosed, corrupting the file system to a point that all the goofy tools out there still can't fix it. For some reason, booting single user mode you can still read the data, then shove it off onto a firewire drive.