Microsoft (NASDAQ:MSFT) just took the wraps off of a slew of new devices, including its new Lumia 950 and 950 XL smartphones. The devices run on Windows 10, sport Qualcomm Snapdragon processors, and boast high-end features like a 20-megapixel camera.

But despite Microsoft's persistent march into the smartphone world, one thing might keep the new Lumia devices from succeeding: lack of availability. Microsoft said it's only partnering with AT&T for the initial U.S. launch of the devices, and it may add other carriers later. But with Windows phones only accounting for 2.5% of all smartphone sales worldwide, that help may come a little too late.

Click through the slideshow below to find out more about Microsoft's partnership with AT&T and what it means for the future of the new Lumia devices.