So, acording to VGChartz Kinect Adventure sold close to 21mi units since hollydays 2010. In that same time frame it shows that the 360 sold about 36mi units.
Will that 2 to 3 ratio carry foward this generation?
Op 1: No, Kinect One will sell at a better ratio than the 360 one:
Reason: Kinect is this time around a more advanced and integrated part of console ecosystem. There will be more games that will make subtle use of voice/movement comands, along with apps. The advance in VR and AR will demand a powerfull body/head tracking device.
Op 2: No, Kinect One will sell worst than the previous generation.
Reason: Motion gaming is dead. The casual audience Kinect360 and Wii captured between 2007 and 2011 has migrated to smartphones and tablets.