Mupepe, I just got this email from Amazon (though I currently already have a preorder):
"Dear Amazon.com Customer,
Customers who signed up to be notified of Xbox One console availability might like to know that we will have units of the Xbox One available for pre-order on Wednesday, November 20.
Quantities are limited so you will need to pre-order while supplies last, starting at 8 a.m. ET / 5 a.m. PT. "