In a press release today Apple announced that AirPods are now available to order online. Demand has already outpaced supply; when I checked about an hour after the press release was dropped, Apple was quoting four weeks for shipping.
According to the PR, AirPods will also be in Apple Stores and other outlets “next week”:
AirPods will be shipping in limited quantities at launch and customers are encouraged to check online for updates on availability and estimated delivery dates. Stores will receive regular AirPod shipments.
Introduced in September, AirPods were initially scheduled to ship in October, but were delayed a couple of months when Apple said they just weren’t ready.