But I wonder how pre-registrations will really allow AHA to truly measure demand since I am assuming there is not a cash/payment commitment.
A lottery is a double-edged sword: you can't expect a payment commitment with the potential of not getting in, but if there's no financial commitment, the lottery will fill up with people who aren't necessarily committed to attending...
I guess as long as the method of keeping up with cancellations and waiting list is solid, its an improvement from the mad dash and subsequent server crash.
I'm not too worried about getting a spot with 4000 available, but at the rate its growing, 20% wouldn't be surprising...