This is about loading youtube videos using latest embedded format (iframe) inside a webview.
Example of the iframe embed format
Android browsers are utterly buggy what comes to video playback and embedding. It simply does not work across devices. Trying to get it working is just waste of your time. My suggestion is that you don't try to include but simply provide a thumbnail of the video which directly links to YouTube page or h264 file.
Earlier discussion, with a possible solution.
Google Reader-esque optimizing of WebViews on Android