As much as people make fun of Kinect, it sold a lot of units on the Xbox 360 as an add-on. On the Xbox One -- they didn't have a choice -- they had to buy it. But as of a few weeks ago Microsoft had a change of heart, and decided to announce a Kinect-less Xbox One model, much to the delight of its fans. According to Microsoft lead Phil Spencer though, people will "still buy it."
Spencer stated in an interview with Games Industry Biz, "We see millions and millions of people using Kinect today. We've had over a billion voice commands used. The use of Kinect in people's homes is incredibly high. And because people are continuing to use it, it's an area we're going to continue to invest, in terms of making the experience better. And I think that makes building games in that environment even better. Consumers love the device; they love the experience. They'll buy it. They'll either buy it at launch when they buy their console, or they'll be able to buy it after the $399 console; they'll pick it up and add it on later. And we'll continue to make sure that experience is great."
It'll be interesting to see if lightning strikes twice for the Kinect now that people have the option of buying it. It seems like everyone on the consumer side wants it out, though.
Xbox head on stand-alone Kinect: They'll buy it [Games Industry Biz]