UPDATE: If you've got a Nexus 5, Nexus 6, Nexus 9, or Nexus Player, you can now give Android M a try by installing the dev preview. Because this is early software, though, you may not want to install it on your primary device. Once you're ready to go, hit up the Android Developers site and get to downloading.

Just as expected, Android M was announced today at Google I/O.

Google says that Android M will focus on polishing the mobile OS and that the update has six key features. The first is App Permissions. With this effort, Google is simplifying permissions to categories like Camera and Microphone. And with Android M, apps will ask for permission to features when you actually use that feature, similar to how iOS works. Finally, you’ll be able to toggle individual permissions in Settings.

The next major Android M feature is the Web Experience. This includes Chrome Custom Tabs, which run on top of an app and offer a more in-app experience than a built-in browser would. The third feature is App Links, which aims to speed up the time it takes for you to select some content and then open it up in an app. The app can verify itself as being good for a task and then skip the dialog box asking you which app you want to open some content in.

Mobile payments are getting big lately, and Google is responding with Android Pay. As its name suggests, Android Pay is a new payment system for Android devices. Google says that one of the goals with Android Pay is simplicity, and to that end, the feature will allow users to make a payment just by unlocking their phone and tapping it to a payment terminal. Android Pay will support major credit cards like Visa, MasterCard, American Express, and Discover, and Google is working with AT&T, T-Mobile, and Verizon on the effort. Google says that Android Pay will work with 700,000 retailers including Subway and Best Buy, as well as in apps.

One Android M feature that's going to help with Android Pay is native fingerprint support. Google is baking fingerprint reader support into Android, making it easier for manufacturers to include that feature in their Android devices. And when you have an Android device that supports fingerprint authentication, you'll be able to use your finger to do things like unlock your phone, make payments with Android Pay, authenticate Google Play purchases, and more.

The final big feature of Android M that Google highlighted in its keynote is Power and Charging. Android M includes a feature called Doze that will help to reduce your device's power usage when you're not using it. This is done by using a device's motion detection to determine when the device has gone untouched for a while. When it senses this, Android M will put a device into a low-power sleep mode that'll reduce power usage but still allow alerts and alarms. In its testing, Google says that a Nexus 9 running Android M lasted up to twice as long thanks to Doze when compared to a Nexus 9 using Android Lollipop.

Also included in Android M's Power and Charging functionality is USB Type-C support. This means that we'll start to see Android devices with USB Type-C connectors, which are reversible. The feature will also allow you to choose what you want to do when plugging a USB Type-C into your Android M device, like charging the device or using it to charge something else.

If you can't wait to try out these new features, well, you don't have to. Google is making the Android M Developer Preview available today to the Nexus 5, Nexus 6, Nexus 9, and the Nexus Player. Android M will launch in Q3 2015.

Now that it's official, what are your first impressions of Android M and its new features?