At a conference on Steam and the future of PC gaming at its Seattle headquarters today, Valve announced that it would be introducing a new feature to its digital distribution platform that allows remote storage of all game data for Steam games.
Steam already allows you to play any games in your Steam library from any PC. Steam Cloud will extend that service to game data - examples given were a progress save from Half-Life, or your keyboard bindings and option settings from Team Fortress 2.
All such data will be automatically saved to back-end servers, accessible from any PC, and kept forever at no cost to the player, or the developer of the game. There will be no quota or storage restrictions of any kind; even video replays and screenshots can be stored as part of the Steam Cloud.
In practice, this means that you can uninstall a Steam game halfway through, delete all save files, and resume it years later on another PC, exactly where you left off.
The first games to offer Steam Cloud support will be the Half-Life series, CounterStrike and Team Fortress 2, and forthcoming co-op shooter Left 4 Dead. Steam Cloud will be available as part of the Steamworks set of developer tools.
Steam developer John Cook also mention a slew of other updates to the Steam platform that Valve plans for the near future: auto-updating of your computer's device drivers, social features including events and calendar systems, 'official' community pages for games, pricing localised to your country's currency, Amazon-style recommendations and shopping cart systems, and more payment options.