Since Apple has bought PrimeSense and closed OpenNi, I gave up the idea to add a kinect-like device on Poppy (the Capri module was promising :-/ ).
Yet Kickstarter founded of a new device which it is now possible to get for about $400: http://structure.io/
Such device can be useful for people exploring human-robot interaction or grasping/pointing tasks.
The structure sensor is self-powered and connected by usb, drivers are open source and compatible with Linux (arm also ?) so it seems compatible with Poppy architecture. From a hardware point of view, It would only require to create a 3D printed accessory to assemble the sensor with Poppy’s chest. They give the source of a 3D bracket which can be used as example.