YouTube has jumped into the world of widescreen videos.

Announced very late into the evening on Monday, YouTube has made their video play into a widescreen format to support 16:9 ratio content.  The tradtional 4:3 ratio, which most videos have been up until now, will still play fine in the player, they will just be centered inside the player.

Their blog explains the motivation behind this latest change.

We’re expanding the width of the page to 960 pixels to better reflect the quality of the videos you create and the screens that you use to watch them. This new, wider player is in a widescreen aspect ratio which we hope will provide you with a cleaner, more powerful viewing experience. And don’t worry, your 4:3 aspect ratio videos will play just fine in this new player.

Looking at the embedding code that allows you to place the videos on your site, they are still listing at 425 pixels wide, so unless this is changed, widescreen videos could look odd on your site. It is also doubtful most blogs have that much space, so it will be interesting to see what this does those people who post a lot of videos.