"Information about a video is now grouped together in one place and there's a consistent way to get more detail when you need it. This way, unless something's truly useful to you, it doesn't clutter up your page," explains YouTube.
Popular comments are now highlighted, buttons look slicker and playlists have a more intuitive interface. Unfortunately, the description of the video is too short, you need to click on a button to see the embedding options and it's difficult too spot low-quality videos without actually watching them. YouTube removed 5-star ratings, but it didn't find a good way to show if users like or dislike a video. In fact, to see the number of likes or dislikes, you need to click one of the two buttons.