Suggestion: Plugin to control all blogs sidebars/widgets.

I am over at the wordpress forums and found these two threads
http://mu.wordpress.org/forums/topic/12848
http://mu.wordpress.org/forums/topic/14766

They are all looking for the same thing I am, a way to control which widgets show up on all sidebars. This would be great or those of us who need to change advertising on a regular basis.

Has this ever been considered as a new plugin?