The Amazon cancellation thing happened back in August, too. I want to say it was to Canadian orders? 7sixty came back later and said it wasn't cancelled. We'll have to see what happens in this case.
And as for Gamestop not having it listed anymore, I think that's been delisted since late September. A bunch of people reported pre-order cancellation calls from Gamestop at the time.
Microsoft, apparently.
http://www.facebook.com/pb.7sixty/posts/338093896279949
They seemed to be the final obstacle, at least.