I'm surprised they didn't do it sooner, to be perfectly honest. Same with media, from TV shows to music - although obviously they couldn't get away with using DRM for it. I like Steam because I can keep all my programs on a separate drive and when I reinstall Windows all my games are ready to go, minus the short initial config time. If Valve can do that with other apps - from Office to WinRAR - then that would really appeal to me.
I don't know if anyone else has tried the Office 2013 Preview but one of the best features is the integration with SkyDrive. If Valve can do the same with Steam Cloud then that's great.
"The price of freedom is eternal vigilance."