The code you speak of is generated by a function called rsd_link() in /wp-includes/general-template.php and then added to the header using an action in /wp-includes/default-filters.php (line 159 for wp 2.2.1).
The nice thing about actions you can undo them in plugins. So make yourself a plugin file and add the following code:
remove_action('wp_head','rsd_link');
And it’s gone.
The plugin doesn’t work for me unfortunately.
