Microsoft has previously announced the partnerships with Comcast and HBO, but the deals had not been previously implemented.
The company had previous said it would launch the HBO app ahead of this Sunday's debut of the new season of the series of the popular series Game of Thrones.
Microsoft more and more is pushing the Xbox and its accompanying online service as a device for consuming entertainment beyond games. The company notes today that total hours spent on Xbox Live is up 30% year-over-year; that entertainment app usage has more than doubled over the same span; and that Gold members spend an average 84 hours a month on Xbox Live.