myplugin.php

<?php
/*
Plugin Name: My Plugin
Author: Jesper van Engelen
Author URI: http://jepps.nl
*/

/**
 * Main plugin class for My Plugin
 */
class JWMP_MyPlugin
{

	/**
	 * The one (and only) instance of this class
	 *
	 * @var JWMP_MyPlugin
	 */
	private static $_instance = null;
	
	private function __construct() {}
	private function __clone() {}
	
	/**
	 * Get the instance of this class, insantiating it if it doesn't exist yet
	 *
	 * @return JWMP_MyPlugin Class instance
	 */
	public function get_instance()
	{
		if (!is_object(self::$_instance)) {
			self::$_instance = new JWMP_MyPlugin();
			self::$_instance->init();
			
		}
		
		return self::$_instance;
	}
	
	/*****************
	 * Actual plugin functionality
	 ****************/
	
	/**
	 * Set up plugin functionality
	 * This is what would be in __construct if we were following a similar approach without using the singleton-pattern
	 */
	public function init()
	{
		// Actions
		add_action('admin_enqueue_scripts', array(&$this, 'admin_enqueue_scripts'));
		add_action('init', array(&$this, 'handle_posttypes'));
	}
	
	/**
	 * Register and enqueue scripts and styles for the admin area
	 */
	public function admin_enqueue_scripts()
	{
		// Scripts
		wp_register_script('mp-admin', plugins_url('public/js/admin.js', __FILE__));
		wp_enqueue_script('mp-admin');
	}
	
	/**
	 * Register custom post types and taxonomies
	 */
	public function handle_posttypes()
	{
		// Register custom post type call
	}

}

JWMP_MyPlugin::get_instance();
?>

otherplugin.php

<?php
/*
Plugin Name: My Other Plugin
Author: Jesper van Engelen
Author URI: http://jepps.nl
*/

/**
 * Prevent the My Plugin plugin from registering and enqueueing admin scripts
 */
function jwmop_prevent_mp_admin_scripts()
{
	if (class_exists('JWMP_MyPlugin')) {
		remove_action('admin_enqueue_scripts', array(&JWMP_MyPlugin::get_instance(), 'admin_enqueue_scripts'));
	}
}

// Actions
add_action('plugins_loaded', 'jwmop_prevent_mp_admin_scripts');
?>