YouTube has improved a lot in recent years which had made this video sharing service quite a favorite among internet user around the world.  YouTube is at present trying out an impressive interface which is code named Cosmicpanda. There are quite a lot of improvements in the look and feel this new interface.

First thing noticeable with this interface is that it has given more importance or emphasize on videos, whereas the present live design has lots more of related contents, comments and lots more.

In the new layout you have video on top and other all contents like related videos, comments, Uploader details all down below. On the main video you have also option to make in different sizes according to your comfort.  

Another impressive feature is you are able to view related (suggested videos) videos in grid view. This gives more related videos on a single page.

Well YouTube has not rolled out this feature, since they are in the trial stage and needs user feedbacks and recommendations for further improvements if any.

You can check it yourself: YouTube/Cosmicpanda.