Ahead of Google's IO conference slated to occur later this week, Android Police has acquired and broken-down the latest APK for Google's "Play Services" and have stumbled on some very interesting game-related findings. The rollout for the latest version (3.1.36) is happening now, but is apparently very slow (none of my devices have received it, yet) - most users are currently running 3.0.27. According to this article, the strings file has more than doubled from 300 to 700 between these versions, so 3.1 is a major update indeed.
While there are multiple things introduced here, what's most interesting is the new section for games, including an option that will at the very least allow other Android users the ability to send game invites. Digging deeper, it's been discovered that this "Play Games" functionality will add leaderboards, player and match-handling, achievements and so forth. In effect, Play Games looks to very much emulate Steam for the PC.
Perhaps the best feature: cloud saves. It's unclear if this would encompass all current and previous games, but I hope that to be the case (and surely, there will be an option to disable that functionality). I have often avoided a game on one tablet just because my save or high-score list was on the other, and there have only been a couple of games that have successfully convinced me to sign up for some third-party cloud-save service. Ideally, if I am getting my games through Google, it'd be nice to have all of my information there, so that it can easily be synced across all of my devices.
Like how Valve handles things with its Steam service, it's very likely that Google would allow developers to ignore its own services and continue implementing their own - or implementing third-party solutions. For Google users, though, that may become an inconvenience quick, especially if you prefer to keep your achievements and saves tied to the same service.
There's quite a bit more information to wade through at Android Police, and I recommend having a look if this interests you. Personally, I think Play Games is long overdue, so I can't wait for it to get here.