If you request a song or genre without specifying the app, it'll remember the last one you used and play it from that. It also lets you find a track name from any music app by saying, "hey Cortana, what song is playing?" Finally, when you say, "hey Cortana," from an unlocked PC that's been idle for over 10 seconds, the app will load in a new full-screen mode, showing information like the weather.
The update also includes support for 19 more games in full-screen mode with the Windows Game Bar (including Battlefield 1, Fallout 4 and Dark Souls III). You'll also get new Windows Ink features, additional Edge extensions, a new Windows Defender dashboard, updated Narrator features, more Windows Update options and new rendering tech for Universal Windows (UWP) apps. In other words, it's a pretty big update -- check the Windows Blog for more information, or, if you're on the Insider track, you can now get it directly. As usual, beware of the release's beta nature and the bugs that entails.