I think it's possible.
Xbox One will be 5.1 million at least by the end of August.
Madden bundle will push many units.
Then Xbox One will release in 30 countries + Fifa bundle. Will provide a 200k-300k boost for the month.
Destiny comes out and preorders are looking to be almost the same as PS4 version. This game will sell millions on the Xbox One
School Starts so people buy systems to play after school/colder weather.
6 million+ by the end of september is possible homies especially if Xbox One is undertracked in other regions like PS4 was!
6.8 million by the end of October
10 million by the end of November
12 million by the end of december