It's clever, but honestly I don't care how smooth it is. Scrolling should simply scroll a view up or down a page. Not invoke animation. We already have established UX patterns for playing media, slowing it down, speeding it up, randomly seeking through it.
It's not so much about playing/slowing/speeding up an animation or video. It's about moving forward and backward through an "experience," as much as I dislike the overuse of that word. I'd suggest it's a natural evolution of the scroll behavior.