Ticket #2938: uncheck-default-category.php

<?php
/*
Plugin Name: Uncheck Default Category
Description: Unchecks the default category.  If no categories are checked, the post will still end up in the default category.
Author: Michael D Adams
Version: demo
Author URI: http://blogwaffe.com/
*/ 

function uncheck_default_category() {
    global $pagenow;

    if ( 'post-new.php' === $pagenow ) {
        echo "<script type='text/javascript'>//<![CDATA[\n";
        echo "\taddLoadEvent( function() { document.getElementById('in-category-" . get_settings('default_category') . "').checked = false; } );\n";
        echo "//]]></script>\n";
    }
}

add_action('admin_head', 'uncheck_default_category');
?>