Game Gifting feature has arrived in the latest Xbox One Alpha and Beta build.

FINAL UPDATE: Mike Ybarra has announced on Twitter that Gifting games feature on Xbox One is now available to all users!
https://twitter.com/XboxQwik/status/930293450926206976
This is a great feature that Xbox has built for its community. Before you gift a game, keep in mind gifting games are region locked. For example, if you gift a game in the US region, the other person receiving the gift MUST redeem the game in the US region. Same applies to every region on Xbox One. With that said, let’s go step by step on how to gift a game on Xbox One:

• First head over to the Store and select a game you would like to gift to a friend as seen in the picture below:

• After you click “Buy as gift” two options are going to appear. The first option is the easiest and quickest way to gift a game to someone on your friends’ list. The second option enables you to send a game to an email address. Choose an option most suitable for your desires.

• After you have done the two steps above, you should be good! The friend/person you sent a gift to should see an Xbox Live message in their inbox with a game code and the name of the game.

 
Original news: It seems like Microsoft enabled Game Gifting for selected Alpha and Beta preview members on Xbox One in the latest 1710 build. According to several community members, you can gift games by either giving the game via friends’ list, or you can enter an email address to send as a gift, similar to what Valve is doing with Steam.
Furthermore, Microsoft excluded services like EA Access discounts, Xbox Live Deals With Gold, and we assume Xbox Game Pass as well from being gifted. Now, we don’t really know if it’s intended as some users (not 100% confirmed) are saying standard sales (sales outside GWG, EA Access, etc.) can be used to ‘Buy as Gift‘.
Xbox Preview team stealthily launched this feature last night, we will be looking for an official blog post from Microsoft to know more about this feature until then stick with us!

Screenshot by Reddit user ‘liamcurtis1718‘