As of Jan 26, 2013, there is also a Global registration office INSIDE the secure area at the entrance of terminal E.
Today I was looking for the one outside the secure area and saw the sign. The officer asked my name and checked his list, and said that I had my appt downstairs.
I arrived 1 hr ahead of my spot. They were busy. A manager took me and approved in 10 minutes, including 6 min video and finger printing. Before arriving to the elevator, I got the approval email.
PS: when I re-entered terminal E, I saw a bunch of people waiting in the GE room inside the secure area, they must have different instruction for the interview.