By the description of the machine at the link in the first post I think people are misunderstanding how this thing works.
Insert boarding pass and door opens. Insert bag. If it tests ok door reopens, if not door does not open.
http://www.smithsonianmag.com/innova...ook.com&no-ist
A patron puts his or her ticket in the machine’s ticket slot, which opens a door to one of the pods. The person then places a bag inside, and the door locks. Inside the machine, various sensors scan the bag for weapons and other banned items. If the bag is determined to be safe, the door unlocks. If not, an alarm goes off to begin a security procedure.
The description in the article doesn't say there is a pass through as there is with the current x-ray systems.
This thing could easily slow down checkpoints to a crawl.
To be useful any screening machine needs continuous flow through.