Well, considering that EBWorld and other stores have already stopped accepting pre-orders, I think that many, many people will be buying one
No, that just means that they've already sold X amount of preorders and they don't want to take any more since they're not sure if they'll get more, or even if they'll get their X amount now.
Furthermore, we don't know what number X is. X could be 200,000 XBoxes allocated to amazon.com and ebgames.com each. X could be 50 XBoxes. The fact that they won't discuss/divulge how many they presold is telling...