I just went to register on the TripKey site, only to find a scrolling message across the top stating that registration is closed until June 4th. So I guess I won't be using TripKey during my May trip. I'm wondering why they encouraged me to sign up yesterday - although it's possible the Facebook person didn't know the company was doing this.
I'm not sure how it will affect those who have registered already, but I would definitely have a back-up plan!