After some research, it is indeed an update for the Google Play Games app. As such, I'm going to change the title to reflect this and move it into the Android section as, in my opinion, an update to an app isn't as newsworthy as new features to an OS.
To summarize the news, Google Play Apps can create a local lobby for Google Play Games-enabled apps, so you can play with people nearby. This isn't a new feature in Android altogether, just some Google Play Games-enabled apps.