YouTube has started using a new type of embed code for putting YouTube videos on external sites.
This new code gives YouTube much more flexibility for things like delivering H.264 video to iPhones and Android devices, delivering HTML5 video (like WebM) to browsers that support it, or using plain old Flash.

Unfortunately, WordPress is still using the old embed code. This means that, even with a mobile enabled theme or other mobile plugins, devices without Flash are not capable of viewing videos YouTube videos embedded on WordPress sites this way.

Until Now.

I have created a plugin, Embed YouTube iFrame, that changes the code that WordPress uses to embed videos, and embeds the new iFrame embed code.

The best part is, you don’t have to change anything about your posts.
There is no shortcode to learn, no HTML to fiddle with, no settings at all. You just install the plugin and, when you include the URL of a YouTube video in a post, WordPress will fetch the mobile-capable iFrame version to embed.

This plugin is already in use on several high traffic video blogs and, as with all of our plugins, we are committed to supporting and updating the plugin in the future should the need arise.