https://www.gamespot.com/articles/xbox-one-x-pre-order-guide-release-date-price-game/1100-6452672/

September 19 update: GameStop has announced that it will offer pre-orders on the standard edition Xbox One X beginning on September 20 at 10 AM PT/1 PM ET. Quantities are likely to be limited. The retailer will also offer optional layaway bundles, as well as up to $200 in credit for PowerUp Rewards members who trade in their existing console toward the new system.

August 25 update: If you've had trouble pre-ordering an Xbox One X, this might be why: Microsoft has announced it is the fastest pre-ordered Xbox console ever. The Scorpio Edition appears to be mostly sold out--although, again, you might have luck by continuing to check in at retailers that are currently out of stock. Microsoft says details on pre-orders of the standard edition will be shared at some point in September. We'll report back as we receive more information.