Custom query, multiple custom keys

I’m not an SQL expert, but I would think you might have to JOIN twice to pick two distinct rows out of wp_postmeta:

 $featuredquery = "
    SELECT wposts.*
    FROM $wpdb->posts wposts
    JOIN $wpdb->postmeta article_level ON
      ( wposts.ID = article_level.post_id AND
        article_level.meta_key = 'article_level' )
    JOIN $wpdb->postmeta article_genre ON 
      ( wposts.ID = article_genre.post_id AND
        article_genre.meta_key = 'article_genre' )
    WHERE article_level.meta_value="Hovedsak"
    AND article_genre.meta_value="X6.no (Spill og underholdning)"
    AND wposts.post_status="publish"
    AND wposts.post_type="post"
    AND wposts.post_date < NOW()
    ORDER BY wposts.post_date DESC
    LIMIT 0 , 4
 ";