T5 Preset editor post content

t5-preset-editor-post-content.php

<?php
/**
 * Plugin Name: T5 Preset editor post content
 * Description: Default text for post content.
 * Author:      Thomas Scholz
 * Author URI:  http://toscho.de
 * Version:     2012.04.17.2
 */

/*
 * See wp-admin/includes/post.php function get_default_post_to_edit()
 * There are also the filters 'default_title' and 'default_excerpt'
 */
add_filter( 'default_content', 't5_preset_editor_content', 10, 2 );

/**
 * Fills the default content for post type 'post' if it is not empty.
 *
 * @param string $content
 * @param object $post
 * @return string
 */
function t5_preset_editor_content( $content, $post )
{
    if ( '' !== $content or 'post' !== $post->post_type )
    {
        return $content;
    }
    
    return 'This is the <em>default</em> content. You may customize it.';
}