For my blogpost http://websupporter.net/blog/de/starter-content-fuer-themes/

starter-content-add-widgets-3.php

<?php

class Mein_Widget extends WP_Widget {

	function __construct() {
		// Instantiate the parent object
		parent::__construct( 'meine-base-id', _x( 'My widget', 'theme-slug' ) );
	}

	function widget( $args, $instance ) {

		$title = apply_filters( 'widget_title', $instance['title'] );
		
		echo $args['before_widget'];
		if ( ! empty( $title ) ) {
			echo $args['before_title'] . esc_html( $title ) . $args['after_title'];
		}

		echo '<pre>';print_r( $instance );echo '</pre>';
		echo $args['after_widget'];
	}

	function update( $new_instance, $old_instance ) {
		// Save widget options
	}

	function form( $instance ) {
		// Output admin widget options form
	}
}

function myplugin_register_widgets() {
	register_widget( 'Mein_Widget' );
}
add_action( 'widgets_init', 'myplugin_register_widgets' );

add_action( 'after_setup_theme', 'theme_start_content' );
function theme_starter_content() {

	add_theme_support( 'starter-content', array(
		'widgets' => array(
			'sidebar-1' => array(
				'text_business_info',
				'search',
				array(
					'meine-base-id',
					array(
						'title' => _x( 'My own title', 'theme-slug' ),
						'something' => _x( 'Everything could be here.', 'theme-slug' ),
						),
				)
			),
		),
	) );
}