The speaking queue for each room is available publicly, so you can see how many people are in the queue ahead of you. The links to speaking queues for all available rooms are displayed below.
Current Speaking Queue (Public View)
Plenary Room
Conference Room 1+2
Ballroom A
Conference Room 3
Conference Room 4
Ballroom B
Conference Room 6
Conference Room 7
Conference Room 8
Ballroom C
Hall A3
Auditorium
Hall A2
Room 25