YouTube now allows uploading of video files upto 2GB, as well as large HD files directly from your camera. Also, you can now share links directly to the HD version of your video, as well as embed the HD version on your blog or website:

-To share a link to HD version, simply append &hd=1 to the end of the URL to play in HD format.
-To embed HD version, click the 'customize' button to the right of the embed box on the video page. Some options will appear; simply check 'play in HD'. The embed code that's generated will cause the video to start playing in HD as soon as a viewer clicks play. It’s recommend embedding HD videos at the largest size (853x505) for maximum enjoyment.