Ever heard a developer say they just pushed an update (and in some cases a brand new app) to Google Play, only to go to Google Play and see the update isn't available yet? That's because Google Play has a process it goes through when processing updates. Essentially it's pushing that update to all of its servers around the world. So it typically takes a couple of hours before the update is available on Google Play. Well Google has changed that a bit this week.
Now when a developer uploads an update to their app to Google Play, they can click the "Go Live" button and have it available to everyone at once. Google does note that it could still take a few minutes, but it won't take hours like it has in the past. Some have been confused and thought this also includes the ability to schedule updates. And that was based on how Google worded the update in their support docs. Developers can choose to have everyone get the update at once, or do a staged rollout. But not scheduled updates...yet.
This only works for App updates. Not brand new apps. So if you have an update you want to go live for everyone at the same time, easy as can be. But for those that are publishing a new app, it's still going to take a few hours to show up for everyone. Additionally, there is still a bit of processing that these app updates must go through before it will be available for everyone. Finally, developers won't be able to revert changes. So you'll really want to be sure you squash all of the bugs, or at least the big ones, before making it live for everyone.
App updates are always a bit of a tricky things. End users like us want the update as soon as possible. But that's just not possible due to the number of Android users out there using Google Play, as well as making sure the servers around the world are all in sync with each other. But things are getting a bit easier, and that's a good thing.