Microsoft is throwing a House Party on Xbox LIVE in February and they are generally bringing quite a few new games to their Xbox 360 and Windows Phone 7 between the PC classic Torchlight in an HD remake of Beyond Good and Evil together with Hard Corps Uprising.
The announcement of the House Party promotion came following the Microsoft CES keynote with promises to kick them here back on February 16. Hard Corps Rising may be the first game but no schedule was presented with as to if the rest are going to be released. Presumably it will likely be one or two games per week over a month-long period and include some other type of incentive to buy all of the games like previous promotions.
These are definitely the games as outlined by a Microsoft pr release.
Xbox Live Arcade:
Windows Phone 7: