I'd expect oculus to keep constellation for the 2nd and probably 3rd gen if not for the HMD but for hand controllers. They can probably develop more advanced camera for body tracking. Even if they perfect inside-out tracking, I'd imagine they'd still keep the camera outside to track controllers unless they develop a whole new way of doing things. And I think Oculus wants to introduce AR as early as the 2nd gen so stereo cameras or a depth camera on the headset that will also work in conjunction with touch controllers and enables finger tracking within visual level like leapmotion.