This afternoon, Google decided to release the Android N Developer Preview a bit early. Typically we see it get released at Google I/O after the opening day keynote is completed. However it appears that they are doing things a bit different this year, considering Google I/O isn't until May. Those with a Nexus 6, Nexus 6P, Nexus 5X, Nexus 9, Nexus Player and Pixel C can play around with the developer preview later on today!
In Android N, Google actually changed up the notification shade quite a bit. One of the new features is Quick Reply. The feature isn't new actually, as third-party developers have been using it in their own apps for quite some time. Additionally, Hangouts and Google's Messenger apps added it in recently. With Android N, Google has created an API for Quick Reply, allowing developers to built it into their apps and allow users to reply to messages from within the notification shade, instead of opening the app and replying. Not a huge deal, but definitely convenient.
Another feature added to the notification shade it notification bundling. For some, this might be a small feature, but it is a big one, especially for someone that's get a lot of notifications. While we've already had notification bundling to an extent, in Android, N really builds upon that feature. For example, with Gmail, you may get 5 or more emails when you're asleep, however you can't do much with them without going into the Gmail app. Now, with Android N, you'll be able to unbundle these notifications and deal with them individually without heading to your inbox. Meaning you will be able to archive or delete multiple messages without jumping into the app.
Quick Settings has also changed in the notification shade. So at the top you'll see icons for WiFi, network, flashlight, do not disturb and battery. There is also a down arrow which will expand and give you even more information and toggles to play with. It makes things a bit easier, especially if you just want to toggle WiFi on or off.
It's worth mentioning that things we see in these developer previews may or may not be in the final version when it hits in the fall. As we saw with Lollipop and Marshmallow, some features were deemed "not ready yet" for the stable release. And that will likely happen again with Android N.