recent-posts-shortcode.php

<?php
function my_recent_posts_shortcode( $atts ) {
  extract( shortcode_atts( array( 'limit' => 5, 'categories' => '' ), $atts ) );

	$q = new WP_Query( 'posts_per_page=' . $limit . '&category_name=' . $categories );

	$list = '<ul class="recent-posts">';

	while ( $q->have_posts() ) {
		$q->the_post();
		$list .= '<li>' . get_the_date() . ' <a href="' . get_permalink() . '">' . get_the_title() . '</a>' . '</li>';
	}

	wp_reset_query();

	return $list . '</ul>';
}

add_shortcode( 'recent-posts', 'my_recent_posts_shortcode' );
?>