I'm going to be very cynical and say that based on their track record of major OS overhauls I am _not_ looking forward to the bugs and issues that will sneak past their QA. I still have nightmares of all the bugs with their wifi & USB stack changes in the last couple OSX releases. Please Apple, for your own good don't 'move fast and break things' with the filesystem. At the very least it's time for everyone to make sure they have a good backup system in place before touching this thing.