[G] Steam Game Sharing Feature Spotted in Code

"Steam may soon be introducing the ability to share games with friends, if a few lines in the client code is anything to go by.
Originally spotted by NeoGAF, three lines of code found in the latest Steam client beta make reference to something called a "shared game library", which has caused speculation that you may soon be able to share your purchases with mates. The relevant lines are:

• "SteamUI_JoinDialog_SharedLicense_Title" "Shared game library"
  
• "SteamUI_JoinDialog_SharedLicenseLocked_OwnerText" "Just so you know, your games are currently in use by %borrower%. Playing now will send %borrower% a notice that it's time to quit."
  
• "SteamUI_JoinDialog_SharedLicenseLocked_BorrowerText" "This shared game is currently unavailable. Please try again later or buy this game for your own library."
  

As it currently stands, once you buy a game on Steam it's tied to your account, meaning you're unable to trade it, sell it or lend it to a friend as you would be able to with a physical disc.
From the code, it seems like you'll be able to let other Steam users play your games when you're not using them, but they'll then be told to quit should you wish to play.

While nothing's been confirmed, it'd certainly be an interesting turn of events in the light of the Xbox One's game sharing plans. Could Valve be about to take a leaf out of Microsoft's book? Let us know what you think in the comments."