Don Mattrick’s just announced that Activision and Microsoft has entered into a deal which sees all DLC from Call of Duty: Black Ops coming to Xbox Live first before anyone else in a three-year deal.
So, this means, that like the Modern Warfare 2 DLC Xbox 360 users will get it first.
For three years. Probably by a month if the current schedule is maintained.
Call of Duty: Black Ops is due for release in November this year on PC, Xbox 360 and PS3.