While this is technically the third developer preview released for Android N (Dev Preview 1 launched a month-ish back) its got some new API changes baked in that should make Android N better for everyone.
For starters, there is a new 3D rendering API to help smoothen out performance for “draw-call heavy applications” that’s called Vulkan. Its likely designed to make heavy duty games run better, and there’s also a handful of bug fixes going with the update. Apps will also be able to define intent shortcuts, which can then be added to the launcher for ease of access. For example you could have a shortcut that immediately starts you on the way home using Waze or a shortcut that would let you message a particular contact at a click.
Last but not least, you will get Emoji Unicode 9 support out of the box for more “human looking” emoji with more skin tone variation and Unicode 9 glyphs.
If you’re already on the Android N Developer Preview, you should get this update automatically. But if you want to try it out, you’ll have to join the Android Beta Program and own a Nexus device to test it out. You can check out the update in its entirety here.