According to blog Eurogamer, Xbox Live's cloud saving is now live, making it possible to recover Gamertags across different consoles and access save data. It apparently doesn't yet work for all games, however. [Eurogamer]
The story and report is complete nonsense, many arcarde games had "cloud saving" since forever. Nearly every arcarde game where you are not presented with a memory unit choose dialog saves the little save data it has (unlocked level, etc) into your profile. That is synced when online and gets recovered when you recover your gamertag. It has been like this since launch.