While the name might raise a few eyebrows, the premise behind Valve's "Steam Cloud" will certainly lead to some standing ovations. As part of the RPS live blog feed from Valve, the "Steam Cloud" system will handle configurations and save files across multiple computers!
Save games and configs are to be stored by the Steam back-end. Half-Life will be the first to do this, with Counter-Strike remembering your key config. Left 4 Dead will ship with this too.

If you’re offline it caches the data locally, and then uploads it as soon as it can. They will keep those save games forever. "You can uninstall Half-Life, then come back to it two years later and finally finish Xen."

It will be free, to both developers and customers.
This new system is going to be huge. Not just for Steam users, but for the PC game community as a whole, especially if other companies opt to roll out their own "Steam Cloud" like system.

no more loosing of my cod4 levels?

everytime i reinstall my windows i save my profile , u can find it here : D:\Steam\steamapps\common\call of duty 4\players

They aren't limiting this to steam, so any game developer can make use of this.. let's hope this will become a standard for all games <3

There are actually people who hate steam.. I thought it was a myth

No, they DO limit it to steam, but not to VALVe only games

Wicked awesome, too bad I have retail version of CoD4. I have to keep a backup of my profile on my email =/