Well the software will sell big no question.
It will move systems, but how many I'm not sure. The Kinectless X1 is only 29th right now compared to PS4 in 7th on the bestsellers list, seems like that isn't quite the 'megaton' people were talking about, so maybe Halo is the only thing that can really push X1 forward.
It will also be hard to judge just how many systems it sells given it releases in the holidays when sales rise exponentially anyway







