According to Android Police, who've gotten their hands on a leaked Google Play Services update file, Google will be rolling out a multi-player social gaming network called Google Play Games. The gaming network will be similar to Apple's Game Center for iOS and Microsoft's Xbox Live for Xbox, and will feature gaming network staples like leaderboards, achievements, invitations, in-game chat, matchmaking and more.
The code also indicates that the network will also be able to save your game data into its servers (the cloud), so that you can continue playing your games even when you switch devices. And like most of Google's services, Google Play Games will also be tightly integrated with Google+ so that users can post high scores there for all to see. There are also some unanswered questions that will most likely be answered during the upcoming Google I/O.
The big question I have right now is, "is this all there is"? Will games handle all the client-side UI stuff that isn't here, or will we see a central game app come out of Google? A lot of stuff doesn't work right now, so we're definitely missing pieces, I'm just not sure if that's a server thing somewhere, a central Play Games client, another Play Services update, or up to game developers. We'll have to see at I/O.
Source: Android Police