You would have noticed the wide video format when you visited Youtube today. Yes, YouTube now display 16:9 wide format video. The dimension of the video is 640×360 pixels. Now you can start uploading your HD video in wide format.
Here’s the sample screen shot…
Thanksgiving Video in Wide Format
However, when you embed it at your blog or website, the codes will display in 4:3 format. You will need to tweak the dimension manually to fit in wide screen format so that you will display it in 16:9 aspect ratio.
Don’t forget to add 25px to the height to cater for the control bar. For example, width=425 and height=266.
And if you want to know how to upload your video so that high quality option will be enabled, read YouTube High Quality How-to
To embed high quality Youtube video, just &ap=%2526fmt%3D18 to the URL.