Update: Microsoft has now removed the reference to the Lumia 950 in the offer details, so it looks like this offer is just for the Lumia 950 XL. The offer has also popped up on the Canadian Microsoft Store as well.
Original Story: After coming out with similar offers in other countries around the world, Microsoft is now offering the Continuum Display Dock peripheral as a freebie for early buyers of both the Lumia 950 and Lumia 950 XL in the US.
The offer very much reflects a similar one revealed for Germany and the UK in late October. From the Microsoft Store listing:
Eligible for free Microsoft Display Dock with purchase of Lumia 950 or 950 XL via the Lumia Offers app, while supplies last.
Curiously, while the offer details appear on the product page for the 950 XL and mention that the freebie will be available for the 950 as well, the same details don't appear on the 950's product page (see update).
Moving down to the fine print of the offer, it looks like it is available with valid purchase and registration between November 25 and January 31, 2016 while supplies last. Buyers will then have until February 29, 2016 to redeem their promotional code from the Lumia Offers app on the Microsoft Store.
Keep in mind that neither the Lumia 950 nor the 950 XL are yet available to order from the Microsoft Store in the U.S., but you can check out the details on the product page at the source link below.
Thanks for the tips, Junaid, Chris, and Tanner!
Source: Microsoft Store