"Hey Siri" support and possibly wireless charging case alongside AirPower charging mat.
Costco Begins Selling Select Macs on Web at $50 to $200 Discount
Costco's member-only prices are between $50 and $200 lower than Apple's prices for select Macs. The base model 2018 MacBook Air with a 1.6GHz processor, 8GB of RAM, and 128GB of storage starts at $999 at Costco, for example, compared to $1,199 on Apple.com. There is a limit of two per customer.
The wholesale retailer is accepting pre-orders now, with shipments expected to begin the week of December 17. In-store pickup appears to be an option, but it's unclear if Costco warehouses will be selling Macs to walk-in customers.
An annual Costco membership starts at $60 in the United States.