Thanks for your plugin.. So far i just tried your Custom Permalinks 0.6.1 plugin and handling WP 3.0.1 permalinks specially for post type Page.. but:
1. We still needed and using some generated instead create manually from a new one.
2. Copy from the title into permalink field not automatically replace into lowercase plus with dash although click Update button.
Small edited your code (line 400 & 401)
this.value = ''
this.value == '<?php echo htmlspecialchars($original) ?>'
So we just need to throw away "about-us/" for this example: