wp.org/support-4820935

add_action( 'admin_menu', 'pending_posts_bubble_wpse_89028', 999 );
function pending_posts_bubble_wpse_89028()
{
    global $menu;
    $args = array( 'public' => true );
    $post_types = get_post_types( $args );
    unset( $post_types['attachment'] );

    foreach( $post_types as $pt )
    {
        // count posts
        $cpt_count = wp_count_posts( $pt );
        if ( $cpt_count->pending )
        {
            $suffix = ( 'post' == $pt ) ? '' : "?post_type=$pt";
            $key = recursive_array_search_php_91365( "edit.php$suffix", $menu );
            if( !$key )
                return;
            $menu[$key][0] .= sprintf(
                '<span class="update-plugins count-%1$s"><span class="plugin-count">%1$s</span></span>',
                $cpt_count->pending
            );
        }
    }
}
function recursive_array_search_php_91365( $needle, $haystack )
{
    foreach( $haystack as $key => $value )
    {
        $current_key = $key;
        if(
            $needle === $value
            OR (
                is_array( $value )
                && recursive_array_search_php_91365( $needle, $value ) !== false
            )
        )
        {
            return $current_key;
        }
    }
    return false;
}