Cool, has one bug, and not useful during manual upgrade

This is a very cool and nicely configurable plugin.

One bug fix needed:
site.php, line 95:
Change this:
<?php bloginfo('url') ?>
to this:
<?php echo site_url(); ?>

Otherwise, the countdown timer won’t work, if your Site Address isn’t at the root of your site (i.e. if need to use /wp/wp-includes…).

And, you can’t fully rely on this plugin for any serious WordPress maintenance (such as a manual upgrade), because the plugin is part of WordPress and thus requires WordPress to be in a functional state. An all-purpose solution would involve an .htaccess rule that temporarily redirects to a static HTML files, thus not depending on WP at all.

But, if you have to do it within WordPress, this plugin is great!