[wp-hackers] Programmatic Widget Handling

[Lance Willett]

> I'm currently working on an extension to the widget's functionality to allow users of the site to create virtually unlimited amounts of new sidebars, filter them and add widgets to them.

Might be worth looking at the Widget Profiles plugin:
http://wordpress.org/extend/plugins/widget-profiles/

It's two years old but has the same basic principle in mind.