Handling embedded videos in excerpts

Try this:

global $wp_embed;
if ( get_option('embed_autourls') )
    remove_filter('the_content',array(&$wp_embed,'autoembed'));

// do excerpt/content stuff

if ( get_option('embed_autourls') )
    add_filter( 'the_content', array(&$wp_embed, 'autoembed'), 8 );