Translating step 4
The DK2 includes a brand-spanking-new positional tracking unit. Essentially, it's a custom-made external IR camera, specially designed to work with the new Development Kit.
The Oculus Rift DK2 retains its 360° orientation tracking, with no camera needed—just like the first version of the Oculus Rift. But to get the added benefit of positional tracking, you'll need to be in the external IR camera's field of view.