It looks like changing the dates/time on our clocks have no effect on whether or not you WILL receive the update, just how fast you get it if you were already part of the group scheduled to receive it. It looks like the Google servers picks a list of Xooms that are next for the updates, and pushes those updates to each Xoom on that "list" when your device communicates with the google servers. So, in short, you get the update when your number is called...so changing the dates will not guarantee you an update, you HAVE to be on the next phase list. So those who changed their dates on the Xoom were already on the phase list, they just got their updates faster because they forced their Xooms to communicate with google's servers quicker by forcing an update check. Hope that makes sense guys