Wicked WP Themes - Chapter 6 (Widgets) Question

In Chapter 6 of Build Your Own Wicked WordPress Themes, Allan Cole shows the reader how to register a custom widget-ready area so that it shows up in the “Widgets” admin area in WordPress.

My question is, how can you sort the custom widgets in the admin area? In the example Allan provides, “Main Footer Aside” gets added to the bottom of the widget-ready areas, underneath all the Thematic custom widget-ready areas. Since “Main Footer Aside” comes before the “1st Subsidiary Aside” from a content perspective, it would make sense for future users of this custom theme if the “Main Footer Aside” widget-ready area appeared before “1st Subsidiary Aside” in the WP admin, and not at the bottom of all the other widget-ready areas.

Any feedback on how I could sort the widget-ready areas in the WP widget admin area is greatly appreciated.