My thoughts using the future shipped data...
66.1m -> 1.6m on shelves (maybe little undertracked... 200-300k)
66.5m -> 2.0m on shelves (undertracked... 500-700k)
66.9m -> 2.4m on shelves (heavily undertracked... 1m)
I can't see less than 1 million on shelves for 360 this time of the year... the history sales shows otherwise... I guess there are 1.1-1.3 million 360 on shelves by the end of the year.