This is essentially putting a Kinect in your phone and hooking it up with hopefully high-level APIs. It may take 2-3 years to make it into regular phones, but when it does it will be huge. Apple's acquisition of PrimeSense (the makers of the 1st gen Kinect) means they're also working on this. To give you a real-world example: when I started BarSsense ( http://www.barsense.com ) the core problem was tracking the path…
Essentially this would make it much easier to represent the physical world digitally. But what use cases does a consumer or the average phone user have for digital representations of the physical space around them, particularly given that the user is already aware of the the physical space around them? How can this sort of digital device extend our ability to interact with physical space?