$query_options = array(
	'post__in'       	=> get_option('sticky_posts'),
	'meta_query' 		=> array(
					array('key' => '_thumbnail_id')
				)
);

$stickies = new WP_Query( $query_options );

echo "<p>post_count is $stickies->post_count and found_posts is $stickies->found_posts</p>";

if( $stickies->have_posts() ): 
?>
	<div id="slider">
	<?php while( $stickies->have_posts() ) : $stickies->the_post(); ?>
		<div>Slider content for <?php the_title(); ?> omitted</div>
	<?php endwhile; ?>
	 </div>
<?php	endif;