Google has added some new options in YouTube that makes it easy for you to embed YouTube videos that are available in Widescreen 16:9 format. You can access these new options by clicking the customize icon next to the embed code as in the screenshot.
Here you can see a sample widescreen video clip from YouTube embedded in the blog.
Related: Embed YouTube Videos in PowerPoint
And for regular videos on YouTube that aren’t available in the Widescreen format, you are no longer limited to the default 425x355 dimensions for embedding as there’re a couple of new player size choices available like 640x505 and 320x265. Hat tip Stagueve.