While the 'Start Screen' could still use some work, I really like what they did here. Clean, modern, fresh. Windows Phone 7.x / 8.x looks stale these days. This is not mine btw.
So basically the Concept they did for Windows phone 10 is: Windows Phone with Google's Material Design.
Look to Xbox Video, Music, OneNote for Windows.
And OneDrive for WP. :]