On that last thought, to come up with a valid conspiracy theory, what's preventing Big Oil from filling up the reservation list with hundreds of dummies that they'd cancel just as Tesla reaches the start of production? If not anything else, it'd be poor timing and bad press for Tesla. The oil companies can definitely afford to lose $50 x say, 1,500 - it's less than pocket change for them and they wouldn't be doing anything illegal here.
Haha, I just pictured some evil oil exec in a shadowy room smoking a cigar and laughing maniacally.
Well, judging by the attendance to the event, they could cancel their orders, but the early reservations seem legit. By the time they canceled their dummy orders thousands of customers would have their cars and would be spreading the gospel to others who might happily jump in the vacated slot.