The current HD gap (in 360's favor) for MW2 is 3.2 million, for Black Ops it's 2.5 million, for CoD 4 it's a little less than 3 million, for World at War it's a little less than 2 million.
So if we follow the trend, each subsequent Treyarch or Infinity Ward game has increased the gap in 360's favor.
I predict the following based on this information:
360:
First Week: 7 million
First 10 Weeks: 10.5 million
Lifetime: 15 million
PS3:
First Week: 5 million
First 10 Weeks: 8 million
Lifetime: 11.5 million







