Have you tried resetting to factory settings?
You can press F8 while booting to reset your computer to factory configuration.
I've had the same problem. Got stuck on the we couldn't complete the updates screen. Eventually i held the power button to just reboot. and now i've done that about 10x, hoping it would boot on correctly and no luck. now, it has stopped booting all together. meaning, when i press power, nothing happens. i press and hold, nothing. the blue light does come on for a couple seconds then shuts off.
so i can't even press f8 to reset to factory settings, because i can't turn it on to do so.
help please! i really want this to work. the concept is so great. but the usage so far hasn't been terrific. i'm optimistic...